The film's team says no big statements were intended. Sure. We believe that.
Granted, as hard to buy as these denials are, their claim to meaninglessness does seem entirely possible. Sure, Frank Miller, on whose graphic novel the movie was based, has a political point of view. On NPR's "Talk of the Nation" last month he expressed his dismay about the "state of the home front" and his disappointment at the fact that "nobody seems to be talking about who we're up against—and the 6th century barbarism that they"—by which he meant not just terrorists, but entire civilizations—"actually represent." (He also, incidentally, quoted philosopher Will Durant's line—"A great civilization is not conquered from without until it has destroyed itself from within"—which opened "Apocalypto," another movie that was either a comment on our current political situation—or not.)
Xerxes is demasculinized with painted eyebrows and wears heavy lipstick. If this is not orientalism, then I don't know what is. The great commander is painted as feminine and the movie suggests that he's sexually ambiguous, both in the way he looks and the way he acts--leading to a generalization of an exotic culture. I'm not sure if the film makers were trying to equate sexual ambiguity/feminine characteristic with weakness on purpose, but that's what I got from the film.
Persia is full of mythical creatures and Xerxes will do anything to win this war. This all goes back to the orientalist idea of Asia as exotic and mysterious, where the Persians use mystical magic and animals and plays dirty, while the good old Spartans just use their bodies and spears.