BlizzCon trailer roundup: Overwatch, StarCraft 2 expansion, and Hearthstone add-on

World of Warcraft publisher Blizzard has a busy weekend ahead of it with all of the events its holding at its BlizzCon fan event in Anaheim, Calif., and the company decided to kick off the festivities with several huge announcements.

Blizzard revealed details on the next Hearthstone and StarCraft II expansions. The publisher also showed off a completely new game (its first new franchise in 17 years) called Overwatch, which is a team-based multiplayer shooter.