Fenrir is probably right, although I suppose that they might market it for the Revolution only without the overhaul. That would be bordering on lame, since it wouldn't take advantage of the new technologies that the Revolution has, but then, I think I've heard that the revolution doesn't have that much better graphics than the Gamecube.
About the whole topic of this thread, I'm waiting for Half-Life 2: Aftermath. My 2 main beefs with Half-Life 2 were (1) it wasn't long enough, and (2) it kept too much hidden about what's really going on, like Breen seemed to know more than he ought to, and we still don't know who the G-Man is for sure.