Blizzplanet continues to track down hints at what Blizzard might be planning in the mobile space, i.e. on the iPhone or another mobile computing platform (that Android Dream demo looked pretty sweet, too). Recently, Blizzard posted a job opening for a web software engineer, and while of course that could be for improvements to the Armory, or for the upcoming changes to Battle.net, but considering that many mobile apps are web apps nowadays, that position could definitely be put to work developing a web interface specifically for mobile platforms.
And the second hint is a little more concrete: our sister site Massively has mentioned Vollee before -- they're a company that claims to be able to stream a PC game experience to a mobile platform like the iPhone. They've already created a Second Life client, and Blizzplanet notes that in one of their recent press releases, they mention that they've been working with Activision Blizzard on a partnership. There are a lot of games under the Activision Blizzard banner nowadays, of course, but WoW is the biggest one of them, and it's definitely the MMO Vollee would want to be working on.
Blizzard hasn't officially announced any version or WoW application for any mobile platforms, of course, and even if one was in the planning stages, there's no guarantee we'd ever see it in an releaseable form. But there's definitely a call to bring facets of World of Warcraft to mobile computing, and if they can work it out in a form they find acceptable, it would undoubtedly be popular.