1. A new engine (Unreal Engine 3.0 or something alike)
2. Improved influence system.
3. Harder combat (yes, harder. Not longer).
4. Unlike most people, i liked when you have split up your party, more of that.
5. Romances in KotOR II were the step in right direction, but a more conclusive one this time. No shallow Bastila "save the princess"-scenarios.
6. T3-M4 and HK-47 must be in, they're the C3PO and R2-D2 of the series.
7. Let the story focus on finishing the story of Revan/the Exile, making it end in a huge epic battle.
8. I rather have 6 big, involving and varied planets than 10 dull and uninspired ones. Consistency and balance is paramount.
9. No non-jedi bullsh*t. KotOR is about lightsabers and the force, not blasters and grenades.
10. Have a female Twi'lek as a love interest.