I got to thinking and i have some new ideas.
-Space Combat (same as Galaxies when it comes to customisation, combat etc)
-Fully explorabe planets (again, the same as Galaxies)
-Fully Customizable Items (same as KOTOR2, but customizable looks etc. as well)
-Every time you play it is different! (e.g different quests lead to different storylines. I was so frustrated in KOTOR2 when you played DS and you had to go save Telos, and go and destroy the Sith)
-And maybe, just maybe, The Jedi Knight Series combat, as opposed to turn based.
All these things would make KOTOR3 far more enjoyable.