A job posting reveals Blizzard might be working on a new mobile game2
There are two things that make us believe that the job opening is related to a new mobile title. First, it's for Blizzard's Incubation division, which is the one that deals with new games. And second, one of the pluses listed is “experience developing mobile games”.
We also know the listing isn't related to Hearthstone, since there is a separate opening for Software Engineer (Tools) for the Hearthstone team, with different requirements and description.
So, which franchise would Blizzard take to the mobile scene? Considering StarCraft just went free-to-play, and it was rumored that it might come to mobile, it is a likely candidate. Perhaps, a mobile StarCraft title could play similar to Clash of Clans and other hit mobile RTS games.
Blizzard isn't known for experimenting with new franchises very often, and Overwatch is still at the beginning of its life. That being said, the mobile platform is a completely different one, so perhaps the company might be looking at establishing a new franchise through it.
source: Blizzard via PocketGamer