I'm really liking this game. The mechanics are much improved from HR and exploration has been a blast. Doing a stealth/ghost playthrough first and it's a lot of fun so far.
My only worry is that, based on what everyone else is saying, the story is relatively short and the ending is pretty ****. That's a little disappointing, if true, because Deus Ex has always had such a great narrative.
But who gives a ****? It's new Deus Ex after five years of waiting. The hype is alive and well.