weepul,
Honestly not much. The missions are good and varied to help you accomplish levels. And there is a story running through the game. If you wish to roleplay, there's enough background here to do so and use your imagination. And EA and Westwood have promised a rich and rewarding year ahead of us with regular upgrades and enhancements. They've delivered on that so far.
However, beneath it all, this is still Everquest in space. As I mentioned before there's no "SIM" Here at all. The universe is not truly 3D, it's more like a deep dish pizza pan. And there's no collision detection. You fly right through your enemies, other ships, mountains....
But for 5 days, give er a try.