I don't want to believe it any more than you do, but it's true. I've run the numbers, and friends, the numbers look good. Now, don't get me wrong here, hemo daggers is still going to be awful in any raid environment, but it's got a real shot at taking the PvP world by storm. Let's go over the changes one-by-one and look at how they'll affect rogues.
Rupture: The damage-over-time component of this ability can now produce critical strikes.
So it's our tier 8 4-piece bonus, but as a passive bonus. I can't say this was unexpected, as they did the same thing to Flame Shock for the shaman, who used Rupture in a similar capacity to us: maintain good uptime, and it will enable a more powerful ability for you later. I have been testing it on the PTR, and frankly, I'm not really noticing a DPS increase by including Rupture in my rotation (as combat), but I'm still awaiting some better numbers from the other theorycrafters with a more diverse gearset to figure out just how this change will affect us, if at all.
Now, onto the subtlety changes you've all been waiting for:
Ghostly Strike: If the rogue has a dagger equipped, this ability now deals 180% weapon damage instead of 125%.
Hemorrhage: If the rogue has a dagger equipped, this ability now deals 160% weapon damage instead of 110%.
These two changes prove to me that Blizzard's on the top of the math game, because they basically make using Hemo or Ghostly Strike with a dagger equivalent to using a very slow sword or axe. Here's the preliminary numbers, using a Bloodvenom Blade as the example sword and a Heartpierce as the example dagger:
Hemorrhage: Sword – 648, Dagger – 653
Ghostly Strike: Sword – 736, Dagger – 734
Ghostly Strike w/ Glyph: Sword – 1031, Dagger – 1028
As you can see, the damage is identical across the board. This means that if you've got a decent slow dagger, there's no shame in using it with a subtlety build, and means that Backstab isn't necessary to do decent damage with a dagger.
Hemorrhage will completely revitalize the sub tree, similar to how Mutilate brought assassination back from the dead. It's a low-energy attack that can be used with any type of weapon and will produce an even result, and still allows us to Ambush and Backstab when the situation calls for it (during Shadow Dance or a Kidney Shot, for example). It also removes that pesky positioning requirement that used to go along with spamming Backstab, which is why sub will see some new life in PvP. Subtlety has always had the PvP talents: all the stealth goodies, and both Preparation and Cheat Death make it the survivability tree of choice. With a functional, spammable attack, I could see many more rogues making the move to sub after 3.3.3 goes live.
The beauty of using a dagger with this build is the ability to swap to Backstab for burst, and to use Shadow Dance as the 'killer app' that separates it from any other rogue spec. Hemo itself has always favored quicker weapons as well, since the more attacks you make that benefit from the hemo debuff, the better. The question becomes: do the rest of the changes make up enough of the damage difference between hemo and muti/prep to make the swap worth it?
Filthy Tricks: Now Reduces the cooldown by 5/10 seconds and energy cost by 5/10 of Tricks of the Trade, Distract and Shadowstep abilities, and reduces the cooldown of Preparation by 1.5/3 minutes.
Filthy Tricks is definitely a step in the right direction. It starts off by making Shadowstep free to cast, and cuts its cooldown by 33%, to a measly 20 seconds. That additional mobility becomes key, especially in the fast-paced world of WotLK PvP. Note that the energy reduction on the Tricks of the Trade section does NOT interact with the tier 10 2-piece bonus, so you'll have to be in full PvP gear to see the new Filthy Tricks effect. By lowering the cost of TotT, it also ensures that rogues will have more energy to burst when needed, and that we'll be able to buff our team member's damage at a lower cost to our own.
Serrated Blades: This talent now allows the rogue to ignore up to 3/6/9% of the target's armor, rather than a fixed amount of armor ignored per level of the rogue.
This used to yield about 6% Armor Penetration vs a boss-level mob, and so boosting it to 9% is a pretty big boost to our DPS. It also means that it will interact with any other armor penetration gear we have, which means a combat gear set will be ideal for the subtlety rogue, as you get a free 9% ArP which allows you to gem other things, and can compensate for the low amount of ArP you can cram into a set of PvP gear.
Slaughter from the Shadows: Now adds 1/2/3/4/5% damage to all attacks and reduces the energy cost of Backstab and Ambush by 4/8/12/16/20, up from 3/6/9/12/15.
Here's some of that damage I was talking about: Blizzard's adding a flat 5% extra damage to all subtlety damage. We might as well call this one 'Hunger for Shadows', but I won't look a gift horse in the mouth. In addition to the sizable damage boost, we also get a buff to Backstab and Ambush via an extra 5 energy off either ability. This cuts Backstab's energy cost down to 40, which is pretty cheap considering Sinister Strike costs 40 as well, and they deal comparable damage. Backstab gets a free 30% chance to crit via Puncturing Wounds, so I think Backstab is better off. With such a low energy cost, and Backstab's great % scaling, a Backstab on a Hemo-debuffed target could be dealing some significant damage while not breaking the energy bank. The only issue is the positioning requirement, but Gouge and Kidney Shot can fix that.
Waylay: The debuff from this talent can now be caused by Backstab in addition to Ambush and can be triggered by all hits from these abilities rather than just critical strikes, but the snare component is now 50%, down from 70%.
Here's the change that has me wondering what Blizzard was thinking. By nerfing the snare component, they remove the usefulness of this talent. We're still going to have to use Crippling Poison to maintain a 70% snare on our target at all times, so it doesn't save us a poison on one hand. Ambush had such a high crit chance that it was nearly guaranteed to be applied, although the addition of Backstab to the proc'ing abilities does mean that it will be harder for a class to dispel-spam our poisons. The Waylay effect is physical, like Daze, so our targets won't be able to escape if Crippling Poison happens to be dispelled. The only trick will be using Backstab enough to keep this active though if they're running away, we should be seeing their back anyway!
I can't wait to try out a hemo dagger build on live servers, and I've actually started a full refresh of my PvP gear to accommodate the spec's requirements. I need to get my hands on a great MH dagger to really make it work, as Hemo and Ghostly Strike are still non-normalized abilities, and PvP is all about the burst. I'm not sure if Blizzard thinks the spec is quite 'done' enough for raiding (and the intial numbers don't look good), but I will say that they've got me excited about having the old Shadowstep mobility back, and they even improved on the original.