Pure speculation - and IMHO it's not going to happen. But still, Information Week tells Microsoft has a special acquisition deal with Nvidia. They claim, that in Nvidia's earnings report there are some hints of third party acquisition plans. And this would basically be Microsoft, based on their ten year old deal with Nvidia (Xbox1 GPU).

If the main target is to beat Google, then this would make sense. Google has been building it's future technologies on Tegra platform. With Nvidia chips and Nokia partnership Microsoft would be pretty well prepared to fight for it's market share during the coming years.

Source: http://www.informationweek.com/news/...news/229900137 (retweeted by vivainio)