I wasn't very enthusiastic about this project after seeing the early character stills - the only person who seemed pretty legit was Fassbender's Magneto. Now this is just a teaser, but the focus seems to be squarely on X and Magneto - and it's definitely the best looking in terms of action potential. I guess I shouldn't doubt Matthew Vaughn so much after Kick-Ass, but his earlier quibbles about the fast turn around Fox demanded to get this movie out by this summer had me dubious about X-men's quality.
I am still a little miffed at some of the anachronistic elements, but maybe they really can explain some of the problems away.
Oh yeah, and here is a bonus trailer: it's the Captain America trailer as it should be.