Dual wield nerf in 3.1
If we didn't want death knights to dual wield, then we would have just removed the ability for them to dual wield. However, the damage DKs could do with DW was absurdly high in some cases, and that became the standard to which all other classes were comparing themselves. Hmm, if DKs are doing 6500 dps, then clearly my spec can anticipate yummy buffs in 3.1.
DKs are a new class without four years of theorycrafting history. Some of the current builds being used were not the ones being used originally -- they developed over time as players experimented with mixes of specs and gear. As good as the community is at theorycrafting -- and it is very, very good -- not many people can look at a list of changes in a vacuum and predict what builds players will be using a couple of months from now, especially for a new class like this.
We think there will be other DW builds that develop. Some we have in mind and some no doubt the community will surprise us with. But we think the pendulum had swung too heavily away from 2H for the class. To be sure there were some 2H builds whose damage was also too high, and we have nerfed those as well.
DW always dominates in classes for in which it is an option. This is not the first time we have attempted to scale back DW DKs, but previous nerfs and ability changes were not successful. It is that hard to reign in DW damage.
If we never again see DKs pick up one-handed weapons, then we will make changes to prop up that playstyle more. But I have tried to be very clear that we do not want to see the entire DK class gravitate towards DW as the only sensible way to do dps, and that is exactly how it was trending. We needed to change the trees so that something existed besides hybrid builds trying to skim the best talents off of all three trees. That meant the deep talent trees were not competitive, which is why we made so many changes. (And no, when DKs were already doing 6000+ dps, we weren't going to inflate those talents to compete with hybrid DW builds.)
I will also offer this: While we are happy that we've had so much success not having a single tanking tree for the death knight class, I wonder if it was a mistake to also try and do the same thing with dual-wielding. Perhaps it would have made more sense to stick several DW talents in say deep Frost (though it could have been any of the trees) and left the other two as 2H dominant. It would have been a lot easier to balance. That isn't the direction we are going for 3.1, but it is an interesting idea and maybe my suggesting it will spawn some discussion.
Overall, this class is still in amazing shape. While I can understand if you just really loved the DW playstyle, I think some of the drama on this thread is a tad overblown. (Source)
How "finished" (for now) are the talent trees we're seeing on the current 3.1 PTR?
They aren’t finished at all. However, I would not turn that into many threads saying “Oh, the next PTR build will fix all these problems. Let's just wait to discuss then.” We want feedback now or we would not have put the PTR up.