Ideas and problems; (note that I may be answering things others have answered before, there's a LOT of posts to go though lol)
I'd like, as many others have already said, the option to play as races other than human. The choice of race should also have an impact in the game-a group that is xenophobic should not give you a mission if you happen to be playing a Wookie. On a related note your appearance based on alignment should sometimes be commented on-'Whats up with your face?' if you are darkeside for example.
(Note; I've seen a few people asking to play a Mandalorian. It is worth noting that in KOTOR 1 Canderous says thats Mandolarians don't have any force sensitives amongst them, so no Mandolarian could become a Jedi or a Sith. The closest you could get would be a player who was raised as a Mandolarian like Mira was)
It would be nice if there were more choices when crafting your chars look, maybe there should be the 'normal' portrait system as it currently stands, but there could also be a system akin to the one use in games like the Sims 2 where you can alter the look of your char at will.
Your char should have a history that you can pick from the beginning of the game, such as being a medic before being trained/doing whatever you were doing before the game. This should give you a minor boost to some skills, even if they are not related to the class your playing.
Some feats, such as Jedi Defence, should increase the more they are used. It seems a little strange that you could play the whole game armed only with a lightsabre and not get better at using it to deflect blasters.
Some new races as NPC's would be nice, I'm getting tired of dealing with Rodians, Twi'leks and Duro's everywhere. What about Bothans? Mon Cals etc?
Why does your Char have to know every language? If there are some languages your char can't understand but some of the NPC's can it would force you to take different team members along instead of always taking the same two.
Force jump for guardian classes should be a selectable attack, instead of being triggered by a standard attack on a target at range. Nine times out of ten force jump doesn't work and I never know why. Come to think of it why does force jump only work if you have a lightsabre in your hand? It would make more sense if it only applied to melee weapons.
A simple way to ballance combat with single, dual-blade and twin lightsabres would be to limit which forms you can use with each type of weapon. Maybe you can use all forms with a single blade, but only two or three if your using two sabres.
(Note-In answer to a question I've seen before there would not be any more lightsabre forms-it is, as far as I'm aware, now cannon that there are only 7 lightsabre forms)
I like the idea that you might start with a 'Training' Sabre, one that can't be upgraded and maybe does less damage than normal.
Side quests for some of your NPC's that don't involve the main char would be good. Instead of simply having to talk to someone to train them as a Jedi maybe they have to do a small quest instead. It would be good if they received a training sabre of their own if they complete the quest, more than once I've had a party full of Jedi but no lightsabres to give them. If they get killed on the quest them they should be dead period.
No more furballs in the party, I'm tired of Wookies. They are annoying and, frankly, I keep wanting to shave the fury things just for fun.
If you can choose the alignment of both Revan and the Exile then that should also have a knock on effect on which chars from the first two games you might run into, or that might join you. If Revan was LS then maybe you could add an older (and less annoying) Mission to your team. You should also be able to pick if people join the team, having the option to turn down the chance of them joining you at a later date.
More quests and problems that require, or that can be solved using skills would be nice. Most of the time you can get away with having no skills at all. It would also be nice if the two people you've brought along on quests offer their aid in tasks if they happen to have a higher skill than you do.
There needs to be at least five planets for you to fully explore before you hit the endgame part of the game. While I understand that the developers will be trying to limit the number of disks and not make the game so long that people get bored both of the current games are too short. Only two of these planets, at most, should be places that we've seen before-unless someone thinks to add them as sidequests for NPC's.
Smarter NPC's, not just the ones helping you but also opponents. I don't know about you but if I was part of a large team and three people take them apart in a couple of seconds I would not be standing there firing my gun, I'd be running away very quickly looking for A;Help or B;Someplace to hide. I'm also getting tired of my team mates running off to fight a distant opponent who isn't attacking at that moment. This is to say nothing of their annoying habit of running straight into mines a blind three year old could spot, and why don't the droid's think to use any special weapons they happen to be equipped with.....?
You should be able to construct any weapons and upgrades regardless of your skill levels, what should change is the number of components you'd need to create to create something based on your skill level. This would allow all classes to create the same objects, it would be just a matter of how efficient they are at making them. The better upgrades/weapons should require blueprints to make, either bought or discovered as the game goes on.
Ok, I think I'm done