nah.. its not.. just fooling u... Just like in the commercial u see some dark jedi using Force Crush on some dude in Onderon wen u get Force Crush late in the game. Also the posters of Atris fighting Darth Nihulis (cant spell)... so its just put there for show.
how bout the screen shot in the official strategy guide showing kreia's recommended ultimate gear form or whatever including 2 lightsabers. and 2 hands. i think they changed a lot of story at some point but kept some of the original screen shots and advertising junk
i like how it says "this character's other hand is unavailable for combat" or something like that. it makes it sound like she's doing something disreputable with it.
I think xbox live will have a part where you can get a saber early and give kreia back her other hand. its probably just one of those things that obsideon wants to reel you in with to buy more of their stuff.