I was going to comment to that effect, but you beat me to it. Xerxes was one screwed-up dude, and I wondered how his voice was being distorted (I'm assuming those gold collars he was wearing had something to do with it) every time he had a line.
The historical inaccuracies were a little jarring to me, but not so much that I didn't appreciate the action sequences for their own sake, and not enough to really detract from my enjoyment of the movie. Honestly, from the previews and scenes I watched before seeing it (particularly the MTV clip), I was surprised they paid as much attention to the tactics and formations as they did- the phalanx fighting was near-constant considering the chaos of battle, and their strategic planning was clearly put forth on screen and logical to boot.
I also wondered how many people in the audience realized that Leonidas was offering the most vile curse imaginable when he told Ephialtes (the hunchback) "
" You could certainly see it on Ephialtes's face, that
he knew...
So yes, damn good movie. Not
Lord of the Rings caliber, and it won't win Best Picture either, but it's unquestionably the best thing on screens right now IMO. My first favorite movie of the year. I'll be going to an IMAX screening as soon as I can get a ticket.

That, of course, is the hard part on opening weekend.