Well, don't need to say much more than the title and give you the clip:

http://www.youtube.com/watch?v=ZBKU9WU_wLo&feature=player_embedded

It has Harrison Ford and Daniel Craig (the new James Bond) and Thirteen (from House, if you watch it) or Olivia Wilde if you don't.  The trailer felt a little Joss-Whedon-and-Firefly-ish, doesn't it?

Also, if you have the time, watch this recent interview Harrison Ford did on Conan.. apparently he was drunk, but it almost looks like he is on ecstasy or something maybe?  He can't be THAT weird, can he?  It actually was a funny (if not odd) interview, but in the last couple minutes he talks about ANOTHER Indiana Jones.. and he holds no bars about being as honest as possible about why he'd love George Lucas to finish the script:

http://www.tbs.com/video/conan.jsp?oid=234662

That is one of my favourite Conan interviews ever!  I would put that up with any time he had Norm MacDonald on the show.

But yes, Cowboys and Aliens, although a real B-Movie title, looks to be an awesome movie.