I'm at the library so I haven't even seen this with sound yet but the new international trailer for Superman Returns (which I would guess will be attached to X-Men 3 in the States as well) makes it look like the greatest movie ever made. You can download it in four sizes from this page.
Wait till you see the last shot.
UPDATE: Wow, I take that back now that I see it with the volume up. It was edited poorly, the order didn't work, the pacing was terrible, several shots were held too long, and the voiceovers were pasted together badly.
The last trailer from three weeks ago was made way better.
…but that last shot is still pretty cool.