Just to add some info about dw tank.
I dw since lvl 73 or something, and tested dozens of different builds. Lately, i decided to test razorice, killing machine and some other things. Those things are related to dw frost build.
1st. Razorice, its a great difference. In boss dummies, was a ~150-200 dps gain. In raids with buffs, this meant ~500-600tps increase.
2nd. New killing machine is working great with tanks. Sometimes procs several times in a row, some other times you don't see a proc in 10-15 seconds. But overall, is working good.
Not sure the relevance of those, but this is from the last 25m OS i tanked as dw frost.
Recount - Incoming Melee Damage Report for Eflow
Damage: 220439
Resisted: 21189
Absorbed: 46334
Hit: 64x 28.1%
Miss: 31x 13.6%
Dodge: 58x 25.4%
Parry: 72x 31.6%
The difference between my physical and frost dmg. The main reason why the 5% from razorice worked so well. (there's several shadow and random school dmgs from shields, auras and such that i didnt save)
Recount - Outgoing Physical Damage Report for Eflow
Damage: 105045
Recount - Outgoing Frost Damage Report for Eflow
Damage: 588471
My Dps during the fight.
Recount - Damage Report for Eflow
Total: 854212
DPS: 2978.3
Taken: 0
Time: 276.96s (97%)
Damage Focus: 1.5 (67%)
Avg. DOTs Up: 2.5
How my dmg is spread. (during some part of the fight, one of the elementals was stuck on me, taking some howling blasts)
Recount - Eflow's Hostile Attacks
1. Howling Blast 93 - 327124 (38%)
2. Icy Touch 42 - 110473 (13%)
3. Melee 390 - 102220 (12%)
4. Rune Strike 71 - 95117 (11%)
5. Frost Fever (DoT) 156 - 92769 (11%)
6. Frost Strike 26 - 56538 (7%)
7. Blood Plague (DoT) 71 - 32448 (4%)
8. Pestilence 36 - 13802 (2%)
9. Retribution Aura 61 - 12226 (1%)
10. Blood Strike 13 - 7046 (1%)
Example of how much dmg my skills do.
Recount - Eflow's Hostile Attacks: Howling Blast
1. Hit 56 (60%) (Min: 882 Avg: 2411 Max: 2984)
2. Crit 37 (40%) (Min: 2127 Avg: 5192 Max: 6656)
Recount - Eflow's Hostile Attacks: Icy Touch
1. Crit 25 (60%) (Min: 2720 Avg: 3358 Max: 3704)
2. Hit 17 (40%) (Min: 1129 Avg: 1560 Max: 1745)
TL

R. This is just some data i got from an OS 25m fight. I did around ~5k TPS .. going to 6k and something in crit sequences and several KM procs in a row. I'll try to get a wws of the next 25m raids i tank (i usually only run 10m).
You can see that i dont have a super incredible gear ... only 10man / heroic / badge drops. I believe with 25 man gear, the results would be quite better.
Before people ask, i didnt get icy talons because we have a enc shamy with windfury in 99% of the runs. Frost aura is meh, and Acclimation may be situational but it really helps in some fights (saph, malygos, OS) where you take constant elemental dmg.