I actually got the demo today and was playing it (just got a PS3 today, actually). I only played for about an hour or so, then my pizza came so I quit, and while there was a long intro at the beginning, most of the time I was actually playing.
The battle system is kinda...yeah. I am not liking it. I'm sure I'll get used to it, but it's counterintuitive in a lot of ways. I see what they were shooting for, trying to make turn-based combat look like realtime, but uh, yeah. Not so hot. That said, the graphics are frickin' amazing; there was almost no difference between the cutscene and movie graphics and the game play.