I was kind of expecting the Rogue forums to explode. Two new talents have been datamined from the 5.2 PTR.
Hit and Run
Immediately teleport to a targeted location, leaving a shadow of yourself behind. Upon activating the effect a second time, or after 10 sec, you will return to your shadow's location. 45 second cooldown.
Marked for Death
Mark the target, instantly generating 5 combo points on them. When the target dies, Marked for Death's cooldown is reset. 1 minute cooldown.
You can view all the new (which means those two and a Warlock change) talents here.
There are more changes as well, like for example a Burst of Speed TEST ability that costs 20 focus.
Hit and Run looks great. Not too sure about the Marked for Death ability, but I'm guessing that's a PvP talent anyway. Quite a nice one I might add.
EDIT:
Uhm...
http://ptr.wowhead.com/spell=136679