There is, in all technicality, nothing wrong with this cover. It's nice. It avoids the pretty-girl-in-a-dress cliche. The font choice is good. There's even weaponry!
But it's a bit bland for me and I could never figure out why. A lot of the blogosphere liked it. I thought I'd like it better if I saw it in person, but now that I have the book, it's still meh to me.
While there are things that I can pick out on covers that are wrong - whitewashing, terrible placement, weird color choices - I can't pick out any on here. And yet I still don't like it.
It just goes to show the selectivity of covers to individuals and how we all have different taste.
Have you guys had a book whose cover everybody loved but you found meh?