What about an Explore-the-Galaxy mode? That'd be awesome, and yes, they better have multiplayer.(co-op and vs. if they could manage it) Also, difficulty settings, ships from Ep2. and 3, and DivX video(that's a given though). Outmaneuvering should be simplified a bit. Also, a return of an OK storyline with new characters. Maybe they could implement the Shadows of the Empire storyline somehow....
As far as extras go:
A better designed Music Hall mode, with stop/play etc., and 3D models swirling around as you play in Music Hall like in the original RS.
A better training mode, complete with dogfights, taking out targets and so forth.
And most of all, an option to see scenes from the original trilogy, since the super-duper ultimate edition DVDs are still a ways off.