You can find a longer version of the trailer (1 minute) at
http://www.planete007.com/news_b21_36.php
(in French)
The trailer does seem to give a darker feel to the movie, but I just cant stop laughing when I see the close up to Daniel Craig's face at the end of the clip... just the way he tries to look serious
I liked Goldeneye so hopefully Casino Royale will be good too.