I guess the answer has to be that Microsoft needs to get into Android space, and Android is simply a Google tweeked Linux, so anything that will work with the calls and hardware are gonna have to share somebody's code and Microsoft would rather deal with the GNU foundation rather than Google?
Remember, Ipods and Ipads run a specialized ARM chip made for/by Apple, so using BSD works for Apple but it really isn't Android compatible any more. Heck, Apple doesn't want it to be compatible.
Windows 8 MUST BE ABLE TO RUN ON ANDROID EQUIPMENT or it is all over but the shouting for Microsoft.
Both Linux and BSD were Unix clones, but BSD (and Apple) is a lot closer to real Unix and Linux has drifted slightly further away, and with Android splitting off it has drifted even more further away.
Remember, if mainstream Linux likes something, if they see something neat in Android that they want, they may adopt it into the main Linux kernel tree and drift even further away from the old Unix base point.
Full ARM compatibility as ARM evolves and full Netflicks compatibility and drivers for this and drivers for that -- yup, you could see it coming up in the not too distant future -- especially once Windows 8 creates a nexus point in the next few years that Linux can adopt cleanly since Linux is the root standard, not Microsoft.
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DangerLots of independent programmers hate Microsoft with a purple passion -- if you think attacks on Windows are bad now, wait until the Linux world sees Microchoke trying to take over "their code" and ease themselves into the drivers seat.
It is gonna get bad in about 1-2 years from now when Windoz 8 comes out for ARM and the Win8 attacks begin. The attackers will know that code better than inside out, they will be the ones who wrote it AND maintain it. And the shoe will be on the other foot when key Win 8 drivers and such simply "quit working well" when the patches roll out.
..... use Microsoft's own dirty tricks against them? Poetical justice, ain't it?