It was buffed in 4.2. It was overvalued for some classes, particularly enhancement shaman, because it scaled with several damage buffs and/or masteries specific to classes. So they removed the scaling and bumped the base damage of the proc to compensate - that way the trinket isn't significantly better for some classes than others. For the classes that had no built-in damage boost, it was simply a buff.

Edit: It might have been 4.1 when it was buffed, but either way. That probably has something to do with it.

For this tier, Combat is probably your best bet if you're looking for one spec. It's on-par with Assassination/Subtlety in DPS and has the added bonus of cleave on 2-3 fights this tier. Assassination has the upper hand in Beth'tilac P2 and Alysrazor flying (assuming Subtlety isn't as good for Alysrazor flying - It could be?), but other than that, it's essentially obsolete this tier (ie. everything it does, another spec does just as good or better).

Playing Combat also gives you the option to play Subtlety with minimal reforging changes, but I don't really recommend it. People claim that Subtlety is the top single target spec right now, but I find that hard to believe. I play it myself, but that's only because I enjoy it's playstyle (I played it through the hard times too).

I don't think that it's worth speccing Subtlety for damage, because even if it is ahead on single target DPS, it's not going to be a noticeable difference and the rotation is obviously harder. That said, I consider it a viable spec if you can play it - It's capable of essentially equal DPS to Combat/Assassination, but it's more work for the same output, and if you like the challenge, more power to you.

How do I calculate the EP of an item myself, especially a trinket (assuming the proc rate is at least roughly known)?

Searching for "calculate EP trinket" or similar results in an avalanche. Obviously, I'm thinking of what the Unheeded Warning hotfix did to its EP, and thought it'd be nice to just check myself. I'm assuming the value of its proc is divided by its uptime in some way?

Proc Trinket Value = Proc uptime * proc value + passive benefits.

This calculation is done for Subtlety here and a more general assessment of the trinket can be found here.

No, you must buy your poisons from vendors.

I have a question around getting savage combat up and running, as the provider in my 10 man. I've been kind of faithful to reforging to spell hit, so when I switch targets that my poisons will apply. I'm trying to figure out how to value that versus just reforging to maximize my haste. Is there a formula that I can use to predict how long it will take to get savage combat up given my spell hit?

Trying to optimize this is more than likely entirely in vain, given combat's stat priorities. In combat you will be maximizing expertise and then haste in order to maximize single target DPS. You must consider that these two stats also increase your poison application rate, so reforging to a suboptimal stat when your normal best stats achieve similar results, just to get an extremely minimal (if at all) increase in Savage Combat up-time, is probably a decrease in raid DPS. Another thing to consider is how bad the physical vulnerability debuff is compared to almost all other raid-utility buffs/debuffs. Just an example is the magical damage debuff provided by assassination rogues and various other specs. Magical damage makes up a much, much larger portion of overall raid damage in pretty much all viable raid comps. Not only that, the magical damage debuff is for 8%, two times more potent than its physical counterpart.

In our 25man raid, we have three hunters and two rogues (one being myself) and I think me and the other rogue are going to start tricks'ing each other on the pull instead of the tank. My question is, is there an optimal time to do this? Just before the pull, a few seconds into the fight when everything is proccing, etc.

Tricks of the trade +10% damage buff actually lasts for 30 s... so... just before the pull would be alright :P

The threat lasts for 30 seconds, the damage buff lasts for 6 (ie. the amount of time you spend transferring threat).

@jsz, tricks as late as possible before the pull, as the 4pc procs as soon as you hit the Tricks button, not once it activates (through damage).

It's not.

Glyph drops it down to 10%. Checking being tricksed by another rogue should bump your dps by 2%, not 10%. It's a raid dps tool because it bumps the raid's total dps without boosting your own at all, much like a disc priest can use power infusion as a raid dps boost by putting it on a caster.