They downplayed some (I thought) key points in the story, but a lot of nice details were also in there.
On the upside, Brad Pitt, Eric Bana, Peter O'Toole and Sean Bean were awesome. The fight scenes rocked, especially the one between Hector and Achilles. And it had it's moments, sure :o) I don't know that I'd pay money to go see it again... but I guess it's impressive that they squished 10 years worth of warfare into 2 and a half hours. I think the best part is when Paris "challenges" Menelaus and ends up cowering on the ground clutching Hector's calf. Oh man.
Anyway, the verdict is: definitely go see it. If for nothing else than to see Orlando Bloom and Brad Pitt multiple times with no shirts, and/or buck naked in bed with one or more women. Expect plenty of funeral pyre scenes, and a cameo by Aeneas. Sweet.