Microsoft announced that they have signed a patent agreement that provides broad coverage under Microsoft’s patent portfolio for HTC's mobile phones running the Android mobile platform. Under the terms of the agreement, Microsoft will receive royalties from HTC.
If you are as big as Microsoft it becomes hard to loose. Microsoft gets now paid for successful smartphones that run a "free" OS. Microsoft's Windows Phone is behind the curve, but who it does not matter as they now also participate in the sales of Android Phones.
Apple has recently sued HTC for infringing on iPhone patents. If HTC also settles with Apple than both, Microsoft and Apple get paid on Android phones.
Via this Microsoft announcement.