I notice alot of people posted earlier on about wanting to have Revan and/or the Exile in your party. Fact is... thats pretty much impossible, or at least extremely difficult. If you were to play as Revan or the Exile as Playloud said... you would be taking away what KOTOR good at, and thats giving your character a rich and mysterious background. Even if he/she was in your party, how would go about giving the character a voice, gender, face and skills. Its just too complex, unless you want to end up generating your old characters again (Which would give away the secret).
Personally though... I'd like some things cleared up. Such will the Jedi come back on its feet? Considering the recent amount of events the Jedi has been through (The Mandolorian Wars, The Jedi Civil War, and the Events of TSL). The Jedi Masters are all dead... and the only ones that remain are those dependant on your PC through both KOTORs. Actually the question is will there even BE a Jedi Order.
Heres a nice idea on my part. How about introducing a Companion System. I notice that in both KOTORs most of your party members will argue with each other rather than get along. So how about the option to actually bring your companions together. Possibly only to work while traveling with more than one person. Just my 2 cents.