I played through the opening of Batman: Arkham Assylum before making my way to Microsoft's booth. It was some brutal fun, and the character models were good looking, but I can't say the same for Harley Quinn's character design. Overall it was just alright, the combat flows well and even when you're discovered you can dissappear into the shadows again.
Later: Batman was pretty much everything I expected it to be. We've already seen and heard so much about the game that there couldn't have been too many more surprises. Actually, I would be more excited about the game if the Joker maps were going to be playable at all on 360. Maybe they're timed exclusive, in which case I'll probably pay more attention when the 360 release is more imminent. Until then, the controls were smooth, not so intuitive, but that's kind of a good thing. It means that there is a bit of complexity to the brawler, which will hopefully keep it from being boring. The sneaking around was kind of fun too. Like I said, I was discovered but hoping over the railing and then grappling to the ceiling got me back in my cover of shadow. Batman will ship later this summer.