I'm 99% sure there's been a thread on this already, but neither Google or the site's own search function has thrown it up. So apologies to whoever it was that started the other thread (think it was whiterussian).
Watched it last night, and I can't really make my mind up. It's stunningly shot and that juxtaposes pretty well with the brutality of certain scenes, but for the most part nothing happens. There's lots of pregnant pauses that don't really seem to be alluding to much else. I liked it, but if 300 was essentially a 90-minute long Godsmack video, Valhalla Rising is a 90-minute long Boris or Earth video.
It was a bit (very) po-faced. Aesthetically perfect, but not quite as weighty or interesting as I'd imagine those involved in it's production thought.