Rotten Tomatoes has a round-up of "Beowulf and Grendel" reviews. Right now, it is scraping baaaaarely into the "fresh" category with 56% positive. Their "Cream of the Crop" reviews, though, are far less kind, putting it at 33%.
As for my own review, I've already got it saved on my Netflix queue. The availability is listed for September, though, so I guess I'll have to wait a couple of months to make my own judgment.