So, where will we DPS DKs be in 3.3?
Happy, I hope!
For single target DPS, we've fallen a bit behind other classes. No longer are we the face-roller class - although I expect it will be time before the community accepts that. The link above is to my response to discussions of melee dps in which the only class behind DKs on Saurfang and Festergut is enhancement shammy. And frost DKs just weren't even in the picture.
So why would we be happy again?
First, Frost looks to be back in the picture again!
Primarily, it is getting a 20% personal haste buff that stacks with the raid buff from Icy Talons, and several other abilities are being improved as well. Frost is actually simming out as slightly superior to unholy/blood with abilities on the PTR, although where that ends up is anybody's guess. Some people really like the DW playstyle and more than the others it shakes things up with it's reliance on procs for dps. Glad to see it's looking viable.
Second, Unholy gets options. A frost subspec to get the haste buff, Black Ice, and Endless Winter's strength buff may well be superior in 277 gear to the traditional blood subspec, but both should be viable. Personally, I'm looking forward to going back to a Glyph of Disease spec that I had to abandon during 3.2. The Scourge Strike change is mostly much ado about nothing, but I still like it for the fact that switching to weak adds (like oozes or bone spikes) won't require me to try to spread diseases to them first.
Blood isn't so much neglected as maintaining the status quo - which is a straightforward playstyle, very solid dps (especially single target) spec with some nice buff/cooldowns. Still raging is the debate that in high end gear, armor penetration may outstrip strength for effectiveness. Personally, I don't recommend going full arpen gemming, simply because it's vastly inferior on aoe fights while being marginally - if at all - better on single target. Arpen scales well - and on gear it's great, but I don't plan to gem it unless I get really crazy and obtain a full second T10 dps set (unlikely).
Will the changes put us back as kings of the dps meters? Probably not, although if you work hard you can keep yourself in the discussion. We have tremendous advantages on some fights, while we fall slightly (less than 5%) behind on the Holy Grail tank and spank fights.
All in all, I think we'll be in a good place, and I look forward to experimenting a bit with different specs/gearsets.