OFFICIAL: HBP Back CoverHarry Potter and the Half Blood Prince
UPDATE: Scholastic has released some info about this art. Click the link below to read.
"The back cover depicts Ron and Hermione as well as two other Hogwarts students looking at "the Dark Mark". Drawn in the same green tones as the front cover, GrandPre has created another incredible piece of art that captures the essence and mystery of the Harry Potter books."