I saw a twenty-minute gameplay presentation behind closed doors at E3 and was pretty much left stunned by the game. There's a lot of choices involved in the game - during one portion of the demo I saw, there were at least five ways you could've broken into this building. The same goes with talking to that guy at the bar. There are several ways you could've obtained the information you needed.
I wrote up a preview on it during E3, if anybody wants to read: http://scrawlfx.com/2010/06/deus-ex-human-revolution-e3-preview
I'm loving it so far. Downloaded it last night and played up to Ramona's first boyfriend (it was getting late). The music is simply awesome and totally keeps with the game's retro vibe. When I saw the Mario-like level selection screen, it took me. Need to get some buddies to swing buy and play multiplayer with me. My only true gripe is the game's lack of online multiplayer support.
Hard game, though. Kind of pissed that I missed the trophy for defeating Matthew Patel without losing a life. I haven't checked if there's a way to go back to a single boss fight, but if there is, I'll give it another shot.
On a side note, this reminds me a lot Castle Crashers for some reason.