System
An extended version of the good old SPECIAL system would be a lot better than the corset system aka D&D.
Combat
Everyone will agree that TOEE had great combat, but going for TB combat seems to be wishful thinking nowadays. But maybe, just maybe, you will think about it after the KotOR 2 RT overdose.
Scenario
Everything but Fantasy. Had enough of it for quite a while. There are so many tales to tell in a Sci-Fi scenario, just think of Gateway, Neuromancer or Asimov's robot stories.