It doesn't use UE3? That's a huge surprise. The game looks and feels like a game on that engine. It's also optimized very well, much like a game on that engine. The one thing that made me question whether this game uses UE3 is the fact that AA is readily available on AMD/ATI cards, and it doesn't seem to make a huge impact on performance. MLAA is basically free, while 4xFSAA will drop the framerate average into the high 30's on max settings @ 1920x1200. This game makes incredible use of MLAA. Also, I can't get over the lighting in this game. It's brilliant!!!
Here's a runthrough of the demo in 1080P by yours truly (sorry if I suck):