I'm about 3-4 hours into an early build of "Batman: Arkham Asylum," and while I'm limited due to embargoes on what I can talk about, I wanted to call attention to a rather unique feature which is reminiscent of something that came up in last year's "Prince of Persia."
In that game, you couldn't die. Even if you ran out of health or fell off a cliff, your friendly neighborhood mystical princess flew in and saved you. Batman obviously doesn't have a handy helper that follows him around, but he DOES rely on gadgets quite a bit. So, say you're zipping around the depths of Arkham Asylum and you miss a jump, falling into poison gas or spikes or whathaveyou. Before you land and perish the game will actually slow down and prompt you to hit the grapple button (in the case of the 360 version, the right bumper). Do it fast enough and Bats will shoot out his grappling hook, bringing you back to the ledge you were just on.
It's an awesome touch that, like "Prince of Persia," manages to avoid a fourth-wall-breaking game over screen whenever you fall down a pit. After all, when was the last time you saw Batman clumsily wander off an edge and die?
That being said, you can still die from taking too much damage from enemies and that will result in a context-sensitive game over screen where the arch villain who took you down will mock you into oblivion. It's kinda a best of both worlds, both for hardcore and more casual players.