After reading the PC gamer review of it I immediately preordered it on Steam. They gave it a 94% (same as the first Deus Ex), and said the only problems were some strange boss fights, and a few areas that felt smaller than they should have been. Otherwise, the game sounds near perfect. I haven't seen any other reviews at this time (critic or user, since it's not out yet), so that's all I have to go on, and it's quite high praise.
Also the first is one of the best games of all time. If this game even comes close, but is updated in meaningful ways, it's going to be spectacular, perhaps game of the year material.