IGN had a brief livestream of playing the game with some of the developers today. For the most part it looked pretty good but there was one thing that really bothered me: They showed off part of a boss fight that they admit was unavoidable. After all this talk about being able to play the game different ways, stealth, social/hacking etc. they stick in boss fights where you have no choice and just have to slug it out. Also the fight itself was rather underwhelming. It was just some dude with a ton of hit points and bad aim, leading to a drawn-out war of attrition. It seemed very video gamey (if you know what I mean) and was a startling contrast from the quick kills in most of the game.
In a way it reminded me of Batman: Arkham Asylum, another game with lots of stealth aspects, quick take-downs, etc. but crappy boss fights. But Arkham Asylum at least never advertised itself as a play-however-you-want-to kind of game. Of course it was still an excellent game despite the crappy boss fights, so it's not a death sentence or anything.