I know the subject of characters changing side has been brought up a lot, and I believe Bioware has said that it won't but, I still feel it's a good idea. Either a) make it'll a 4 or 5 mission story line or b) make it just like a server transfer. Either way it should only be for Level 55's or lvl cap and make it a one time deal. The story is over and your in endgame. I think it would be pretty cool to turn my Mercenary into a commando, and maybe keep my 2 blasters.