I think the answer I got from Tom Nichols at E3 this year gives us the answer.
Was there ever a KOTOR 3 in development, or even talked about being developed?
Tom Nichols: No.
I hope it happens, but I just don't think it will. If Obsidian had had more time to develop TSL I think it could have been superior to the original. So between the two developers I would have probably rather seen Obsidian make KotOR 3 if SW:TOR wasn't happening. I guess anything is possible when it can make LucasArts money, but they will make so much on The Old Republic already.
LA will never let Obsidian make KotOR3 because they failed to meet that ridiculous time table.
Hell, all of Avellone's characters are already being retconned out of existence, if that's any indication.
Yeah, it's too bad that BioWare is pretty much not acknowledging the existence of TSL at all.