As is expected from ArenaNet, the trailer is beautiful. Starting with concept art, we actually get to see game footage in a rather long montage of landscapes. And jumping! There is a bunch of that going on, watch for characters running around, exploring this new dimension to their modes of movement.
There is also an FAQ for the game available.
Update: Something is wonky with the server, and it isn’t server the video. You can download it directly (gw2-trailer.ogv), or you can check out the video trailer page.