I saw the Man of Steel trailer in front of Hobbit yesterday. They showed some scenes on the farm when he's younger and they looked good. But conversions are easy to sell in short trailers. I'll be harder to impress when I see the whole movie.
I also saw a trailer for The Croods, which promises pretty and epic environments, but a story that's TBD and humor that's low-brow (multiple jokes about wanting the elderly woman to die during the adventure).
Another trailer I recall was Jack the Giant Slayer. The only thing that movie had going for it were a few shots of Ewan Mcgregor and the shot of Jack lying on his back underwater as the giant walked through the stream. I may be forgetting a handful of good shots but the impression I got from the trailer as a whole was that this will be a mediocre story with mostly mediocre 3D.