In the Scholastic teasers, a disgruntled House Elf is mentioned. While this particular House Elf does not look disgruntled, House Elves in general will probably be a more important part of the plot.
I think this one is Dobby. (Winky has a rounder nose.)
To see the full cover, go to this Leaky Cauldron link.
Hogwarts Tower of Time Entrance
