There might be a third, x86-compatible processor manufacturer who is looking at the mobile market. Intel has been trying to make headway, including the direct development of Android for the x86 architecture. The company also has a few design wins, mostly with Windows 8.1-based tablets but also the occasional Android-based models. Google is rumored to be preparing the "Nexus 8" tablet with one of Intel's Moorefield SoCs. AMD, the second-largest x86 processor manufacturer, is aiming their Mullins platform at tablets and two-in-ones, but cannot afford to play snowplow, at least not like Intel.
VIA, through their Centaur Technology division, is expected to announce their own x86-based SoC, too. Called Isaiah II, it is rumored to be a quad core, 64-bit processor with a maximum clock rate of 2.0 GHz. Its GPU is currently unknown. VIA sold their stake S3 Graphics to HTC back in 2011, who then became majority shareholder over the GPU company. That said, HTC and VIA are very close companies. The chairwoman of HTC is the founder of VIA Technologies. The current President and CEO of VIA, who has been in that position since 1992, is her husband. I expect that the GPU architecture will be provided by S3, or will somehow be based on their technology. I could be wrong. Both companies will obviously do what they think is best.
It would make sense, though, especially if it benefits HTC with cheap but effective SoCs for Android and "full" Windows (not Windows RT) devices.
Or this announcement could be larger than it would appear. Three years ago, VIA filed for a patent which described a processor that can read both x86 and ARM machine language and translate it into its own, internal microinstructions. The Centaur Isaiah II could reasonably be based on that technology. If so, this processor would be able to support either version of Android. Or, after Intel built up the Android x86 code base, maybe they shelved that initiative (or just got that patent for legal reasons).
But what about Intel? Honestly, I see this being a benefit for the behemoth. Extra x86-based vendors will probably grow the overall market share, compared to ARM, by helping with software support. Even if it is compatible with both ARM and x86, what Intel needs right now is software. They can only write so much of it themselves. It is possible that VIA, being the original netbook processor, could disrupt the PC market with both x86 and ARM compatibility, but I doubt it.
Centaur Technology, the relevant division of VIA, will make their announcement in less than 51 days.