Well... I honestly not like it much. The image is ok, but the border around... it looks a bit like step back to old editions instead of leap forward to 4e.
Geez, what's with the Tiefling fetish?
Cool art though. I think the new cover design is nice, but I remember WOTC saying that the books are going to be more magazine, less textbook. This looks like a textbook.
Looks nice. I'll have to hear what's in it, though, and look through it at BAM. If it has a lot of designer talk, I might get it; I'm on the cusp of getting the Rules Compendium just for that.