Your spec is trying to do too many things at once.

On a Pale Horse and Night of the Living Dead shouldn't be in your build - the former is good for a farming build, and the latter is good for a DPS build. Ravenous Dead and Necrosis don't add anywhere near the threat that Dark Conviction, Might of Mograine, or Blood Gorged would add. You should find that the cleave from HS, combined with a glyphed D&D, 3/3 morbidity, and some Blood Boil is just peachy for holding AOE threat - you don't need UB at all.

Butchery is not necessary; you get enough runic power from elsewhere. Mark of Blood is bad because it both scales negatively with avoidance, and because it provides insufficient healing overall, if you think it through logically. Imp. Blood Presence is similarly useless. If you really wanted to reduce incoming damage, you should pick up imp. icy touch (6% reduced damage on you for 3 points is huge).

Enchant the rest of your gear. Never gem with parry gems or strength gems in a tanking set (actually, never gem with parry gems ever, in any gear set). Work towards getting defense capped, so you don't need to rely on the proc from your sigil. Get rid of the Dark Command glyph and pick up the imp Rune Strike glyph (you shouldn't need the DC glyph, and since you should be mashing RS, the glyph will increase your threat a bunch). Get rid of the Rune Tap glyph and pick up either the Vampiric Blood glyph, DS glyph, or IBF glyph- all are much better bang for your buck.

As a blood tank I usually struggle a bit with the initial aoe threat, special if the dps start to aoe right of the bat.
Pretty much every one suggests a DnD > IT > PS > Pest > BT > BB together with a glyphed DnD and 3/3 Morbidity.

Unless I'm reading it wrong Morbidity doesn't actually add threat but it allows you to DnD more offen, from a threat point of view wouldn't 3/5 Black Ice be better, since it would boost DnD, BB and Blood Plague?

Being able to use DnD twice as often should get you more threat than increasing its damage by 6%. The 6% extra damage isn't going to prevent DPS from pulling agro if they go nuts on the pull anyway.

Maybe TankadinTPS may fill your needs.
I'm not sure if it is 100% accurate since the addon-programmer plays a paladin (obviously from the name =)), but it gives me very similar result like Rehfelds TPS-Calc.
The latter is to analyze threat based on a WWS-log.

Thank You Belzi.ET.. i will try it soon...

for instance with my Hunt i'm nearly twice the threat per second of our best Tank...

2 conclusions :
1. I rox hunting... but I don't think so
2. My Tanks suck... but I don't Hope so

There is very, very little threat gain in the first several tiers of Frost for a Blood tank. Improved Icy Touch is always taken (and is taken in my build), so that's out for comparison's purpose. Black Ice is a very minor threat gain, since so little of a Blood tank's overall damage is frost (Icy Touch and Frost Fever) or shadow (Blood Plague and Death Coil). Annihilation is no significant threat gain at all since we don't use Obliterate. That's as far down as we can go in Frost without sacrificing the dodge from Unholy, but even if we were able to get to 4th tier frost without sacrificing survivability, there's no real threat gain there EITHER.

So basically what you're saying is that I should sacrifice a significant amount of self-healing in order to gain 2-3% threat (I'm estimating that frost and shadow damage are about 20-30% of my total damage when tanking with Blood).

No shit, Sherlock. No build can solo heal 25 man Ulduar. I never claimed it could. You, however, are dismissing out of hand with (apparantly) no personal experience whatsoever the fact that Blood does provide a significant and helpful amount of self-healing which can ease the load on healers and help prevent the tank from dieing to RNG. And, as I already covered, I don't sacrifice any real amount of threat to do it.

I have serious doubts (based on my own experience and theorizing) that Blood is anywhere near as good as some people make it out to be, but as far as Blood builds go, yours seems mostly fine to me. I would however drop Spell Deflection for Sudden Doom. Spell Deflection is very RNG, and it also doesn't work on things you'd really like it to, like Fusion Punch or (iirc) Plasma Blast. On the other hand, Sudden Doom isn't amazing, but you do have DRM, so I assume you are Heart Strike spamming, and it's extra threat.

Actually, if I were to respec I'd probably drop Death Rune Mastery. That was more of an intellectual holdover from when I used to tank with Frost or Unholy specs, which absolutely need death runes. I find that the only time I ever Heart Strike spam is in phase 4 of Mimiron and when we're killing trash.

Spell Deflection could probably stand to go, but I don't really know what I'd replace it with. There aren't any other tanking talents in range with just those 3 points. I could do Bloodworms, I guess, but I'd rather not because this spec is my soloing-instances-for-cash spec too and I can't do Hakkar with Bloodworms.

Those points could go into Morbidity/Epidemic for AE threat situations/quality of life, or Butchery/Subversion for minor ST threat increases. Ravenous Dead is also probably viable. Spell Deflection is an aggressively mediocre talent in my opinion.

About Spell Deflection, bosses in Ulduar where it might help:

Ignis:
# Slag Pot - Charges a random target and incapacitates them, inflicting 5,000 (Heroic: 10,000) Fire damage every 1 second for 10 seconds. If the target survives, they will gained 100% (Heroic: 150%) haste for 10 seconds. (maybe? Only if you are offtank and very minor anyway.)

Razorscale:
Phase1
# Devouring Flame - Inflicts 8,788 to 10,212 Fire damage to a player, and additional 8,788 to 10,212 Fire damage every 1 second to anyone within 6 yards of the initial impact, for 25 seconds. (First hit)
# Fireball - Inflicts 12,025 to 13,975 Fire damage.
(these are both random targeted)
# Dark Rune Watchers - Cast Chain Lightning and Lightning Bolt, hitting for ~10,000 and ~5,000 Nature damage respectively. (interruptable)

Phase2
# Devouring Flame - Inflicts 8,788 to 10,212 Fire damage to a player, and additional 8,788 to 10,212 Fire damage every 1 second to anyone within 6 yards of the initial impact, for 25 seconds. (first tick, random target)

XT-200:
none

Iron Council:
# Fusion Punch - Inflicts 18,850 to 21,150 (Heroic: 35,000) Nature damage to his target, and deals additional 15,000 (Heroic: 20,000) Nature damage every 1 second, for 4 seconds. (maybe??)

# Chain Lightning - Inflicts 4,625 to 5,375 (Heroic: 6,013 to 6,987) Nature damage to its main target, and arcs to nearby players, dealing 50% (Heroic: 20%) more Nature damage to each successive target. (interruptable)

# Lightning Whirl - Inflicts 4,713 to 5,287 (Heroic: 7,069 to 7,931) Nature damage to random players every 1 second for 5 seconds. (interruptable)

Kologarn:
# Focused Eyebeam - Two of those will be cast simultaneously, each inflicting 2,775 to 3,225 (Heroic: 4,163 to 4,837) Nature damage, and following their targets. (Not casting on melees, afaik)

Auriaya:
none

Mimiron:
Phase1
# Proximity Mines - Drops 8-10 Proximity Mines around MK II. The mines will inflict 25,000 damage to anyone who walks over them. (You shouldn't hit those anyway)
# Napalm Shell - Inflicts 7,540 to 8,460 (Heroic: 9,425 to 10,575) Fire damage instantly and an additional 4,000 (Heroic: 6,000) every 1 second, for 8 seconds. This spell will always attempt to hit targets farther than 15 yards of MK II. (melee range...)
# Plasma Blast - After a 3-second cast, MK II will channel a stream of plasma for 6 seconds, inflicting 20,000 (Heroic: 30,000) irresistible Fire damage every 1 second to his target. (This might work)

Phase2
# Rapid Burst - Inflicts 1,414 to 1,586 (Heroic: 1,885 to 2,115) Spellfire damage to a random target every half-second for 3 seconds.

Phase3
You should take no spell damage here.

Phase4
# Mines again
# Hand Pulse - Inflicts 4,242 to 4,758 (Heroic: 6,598 to 7,402) Spellfire damage to a random target and all enemies between the caster and the target. (Not sure about this, looks like aoe spell)

Hodir:
# Frozen Blows - Reduces Hodir's physical damage by 70%, but grants each of his attacks 31,062 (Heroic: 40,000) additional Frost damage, for 20 seconds. Enemies take 4,000 additional Frost damage every 2 seconds for the duration of the spell. (Great for this, if it works)

Thorim:
Phase1
# Runic Lightning - Strikes an enemy with a blast of runic lightning, inflicting 7875 to 10125 Nature damage. (10 player: 6563 to 8437 Nature damage) (interruptable)
# Holy Smite - Smites an enemy, inflicting 7650 to 9350 Holy damage. (interruptable)
# Lightning Brand - Shocks the target for 3500 Nature damage to the target, and increases Nature damage taken by 40% for 20 sec. (Stacks to 99)

Phase2
# Chain Lightning - Strikes an enemy with a blast of lightning that inflicts 3700 to 4300 Nature damage. The bolt will arc to additional nearby enemies, inflicting 100% more Nature damage to each successive target.

Freya:
# Storm Lasher - Attacks with Stormbolt for 6,013 to 6,987 (Heroic: 8,788 to 10,212) Nature damage. Also casts Lightning Lash for 5,088 to 5,912 (Heroic: 6,938 to 8,062), which hits up to 3 (Heroic: 5) targets

General Vezax:
none

Yogg-saron:
Phase1
# Dark Volley - Hurls missiles of dark magic, inflicting 8500 to 11500 Shadow damage and wounding nearby enemies, reducing the effectiveness of any healing by 25% for 10 sec. (might work since they seem like direct hit)
Phase2
# Malady of the Mind - Inflicts 5000 Shadow damage and causes the enemy target to run in horror for 4 sec, then attempts to jump to another enemy within 10 yds. Also reduces Sanity by 3%.

Algalon:
Seems to do only AoE damage

# Phase Punch - Massive blow that inflicts 8788 to 10212 damage and slowly fades the target to another plane of existence. (maybe arcane)
----

That should be about it, please correct me if I missed something or was wrong with something. But looking at this list, 3 talent points for Spell Deflection seems very wasted.

Edit; failed a bit with naming and added Algalon

Those are both on Yogg-Saron. Spell Deflection would be useless on Vezax. Its main benefits would come from avoiding aoe and minor raid damage, which applies to most fights (Hodir/Thorim/Freya/Mimiron/Yogg/Ignis/Council). Afaik it does not work on Frozen Blows or Plasma Blast; it may help against Fusion Punch though.