I've always preferred the UK editions over the US editions (although it's the latter that's available here in the Philippines) when it comes to the first six books. But Deathly Hallows will be the first one whose US front cover I adore so much! It portrays so much emotion. Order of the Phoenix and Half-Blood Prince were monochromic! Whilst the UK edition of DH was just...rowdy.
You can also see the pictures here at Wikipedia. Haha! I'm HIGHLY dependent on that witty website. It is also stated that the man in the hood in the US wraparound version is Lord Voldemort.
Also in the above website, it is indicated that at least two of the main characters will die. Rowling stated that "One character got a reprieve, but I have to say two die that I didn't intend to die...A price has to be paid. We are dealing with pure evil...They go for the main characters... well, I do".
Can't wait for July 21st! Well, the 22nd on my case since I live in Southeast Asia.