Revan should be DS Exile LS...
The theory I and Janus made about Nihilus and the Exile that is most likely true should be true in the sequel (you never know maybe they are to lazy to expand on it)
Meaning that if you go Light you will end the force, if you go Dark you save it. Meaning to be the ultimate good guy requires you to stab the Exile in the back and the ultimate bad guy requires you to make the Exile absorb Revan or something causing a chain reaction that destroys the force 😛 Or a less dark less light reaction. Thats four endings and really because it only has to be done in a very small portion of the game it shoudn't create to much difficulties for anybody.
That way it would rule, especially light, you follow somebody your entire life and then at the end you find out you have to do the thing you shouldn't do/don't want to do to finish the game on your own side 😛
One other thing, they should have two starts, this may seem to be asking a lot but a starting map can be pretty easy especially because both should start about the same with just one minor difference in it.
They should also create an extra planet one with a Jedi Academy and one with a Sith Academy, light you go to the Sith Dark you go to the Jedi (from the start at least) That way you can have different starts all the time and a little variation in the planets making the game a bit more fun. At least in my oppinoin you will. And If they don't do anything like that, they shouldn't make it required to follow the Jedi way. I'm sick of killing thousands of Sith when I want to be dark. Those people shouldn't have to be kileld my me, its a waste of perfectly good soldiers that you could send to the front lines to day later on in an important battle.
The only problem with two starts is different characters for some part, at least I would like it if they did, of course they don't have to HK and T3 can be explained to be on other side of the fence, but the one that trains you (Bastila/Exile) would be different and if possible some of the characters you take along. Of course that is not a requirement, I wouldn't really care if they didn't add other characters it will be a lot of work but it would be great fun. And they already tried to do something like that in Kotor II with Hanharr/ Mira and the handmaideni or the disciple.