While KOTOR had ups and downs, I'm sure everyone would like to see more additions and such. Additions is what makes a game fun, unique, and ehh, fun.
I'd like the option to move the interphase bars, or hide them. This isn't a very big problem, but it was irking when I wanted to see a certain thing from a certain angle, and was confronted with my/Bastila/Carth's ugly face.
I'd also like to be able to have a combat camera setting, and when I sight an enemy/mine, it switches to that setting on defualt (remembers my setting). So I would be able to view all my enemies, my path, etc.
I want a bit more tactical planning. The fact that you could use default attack/critical strike all the way was distressing.
I'd like to define a background for my character. What they do now at the start of the game, what they had growing up, where they were born. . .Or maybe a trait that makes them unique, like how Atton Rand can't be knocked out.
I'd like the ability to choose the clothes I wear when I have "clothing" equipped. I found myself wanting to steal Bastilia's clothes frequently. It was, needless to say, distressing.
In the way of PC downloadable content, how about coming out with some new faces every now and then? The female faces were none too attractive.
Final note:
More quests that don't involve killing things! While killing things is all well and good, it can get repetitive. (Unless it's a good Carth killin') I'd like to see puzzles in dialog (think back to the who's telling the lie dantooine quest, please.), more options to be sympathetic or nasty, and multiple ways to do things.
That's all I can think of as of right now. Comments, anyone?