It appears the WoW board game has been successful enough to spawn its own expansion. Fantasyflightgames.com has announced that an expansion is in testing and should be available over the summer, as per their release below.

World of Warcraft: Shattered Kingdom
New treasures, new powers, and new dangers as your heroes adventure in the Shattered Kingdom.

Status: In development and play testing.

Expected: Summer, 2006