I would like to see the True Sith Battles and the Republic, Mandalorians, and maybe even some break away Sith remnants fighting the True Sith(Maybe the True Sith really don't want to share so the regular Sith Troops are like screw this I'm Fighting for the Republic but I'm still a Sith at heart). I would like to see how that all works out and stuff because you know a great war may be lurking soon.
As For Revan I would like to see him as part of KOTOR 3 not as the PC ( I want an average Jedi, a piece of a larger puzzle...like yes they're strong but not be on the scales of what Revan or the Exile was, which was the last hopes, I don't want that for the new PC as well as the whole memory thing) I would think maybe Revan is captured by the TS and the Exile and T3 free him and they make a daring escape(maybe in that instance you could play as the Exile or Revan but for a short little bit at the most)
I would like to see Revan in the Game but he doesn't have to be the main focus I would just like to see if he gets together and stays with Bastila at the end, did they have a kid or something like that(this would happen near the closing credits of course and also depending on how you play the game LS or DS)
Chris Avellone said he could see the present story of KOTOR finishing at IV (I believe he said this, sorry not sure where) if that would be the case III could be finishing up on rebuilding and bulking up troops, worlds and the Republic armada for the big show and then IV could be all the battles or something.
Final point is Revan doesn't absolutly have to be part of or even mentioned if they did make a third game but it's nice to hear about the character we all played as...umm and I mean Revan did play a rather large role in the era that were playing through and he effected many people, worlds and events, so to leave him out would be like a bit of a let down, you know, tiny lil bit, just a smudge.