Improved Sap is now a 2 point talent (instead of 3), and the 2 pt. level always keeps you in Stealth. Plus, Sap never breaks early any more. (At least in PvE) Which means I can lock down a humanoid mob for 45 seconds while I kill his buddy.
Shadowstep (41 pt. Subtlety talent) kicks much ass. It's a short range teleport for Rogues which gives a nice healthy damage bonus to certain attacks that follow the use of Shadowstep. (Right now, I have a 30% damage bonus on Ambush. I'm hitting mobs for anywhere from 1500-2000 points on a crit.)