Although that card was specifically for the Parhelia card it will run with other cards (I downloaded it and it ran ok with my GeForce2), although obviously you might find exceptions given that the demo was written with only one card in mind.
I've heard no talk of another demo, to be honest I'm a little wary since although the graphics of the game were incredible the orders system seemed to work terribly for me (my ships never did anything I told them)... perhaps that's just my commanding but it's never been like that in any other game so I'm inclined to think that isn't it...