It's all old news if you were following the WotLK info.
Shadow Dance is... intriguing. I see it as primarily a defensive ability, although I guess if you saved Energy and then did three Ambushes (or one CS and two Ambushes) I guess it could be okay. Too bad Ambush kind of... you know, blows.
I would drop a point out of Honor among Thieves for CB, though, at least in 2v2; not great, but with prep?
Also, am I missing something about Master Poisoner, or does it just... suck? Good for DP but awful for Crippling or Wounding/Mind-Numbing?
For a theoretical PvE build, probably
this. Prey on the Weak looks insane if you're at high HP, which you should be, and Murder Spree is intriguing although it's hard to tell how effective it is (namely, do you stop doing autoattacks or not). A hypothetical daggers build might be something like
this.
Lots of possibilities, but you'd need to see how some of the abilities play.