Lord Kofun said:
I heard the demo was awful. Don't get too excited, gentlemen.
Edit: I guess I need to annotate that. I love Batman. He's been my hero since I was five. However, I have yet to play a game about him that is anything close to good. So... yeah.
MKVSDC was actually half-decent. It was the best game from either franchise in a decade.
I think Arkham Asylum looks pretty good. I don't have money for games these days, so I can't afford to get too hyped over it, or I'll get really disappointed when it comes out, but it looks pretty good..
When I was playing through Assassin's Creed, I liked to pretend I was batman... Take Assassin's Creed, change the setting to Gotham, make it nighttime, and remove (or make more interesting) the little side missions, and you'd have a pretty decent batman game IMO.