I don't know why people on this forum are so up in arms about this. It's clearly a decision that will benefit MS - remember, WP is nothing more than a sideshow at this time - it doesn't make any money, doesn't sell particularly well, doesn't get favourable reviews and this has been going on for the past 4 years. OF COURSE they're going to go where the sales and money are; as representatives of the shareholder, it is the management's responsibility to do so. And they will, regardless of ****** tears.
MS just bought Nokia, at an expense of billions of dollars. They now have a hardware company.
They must show a return on this investment or watch MS stock tank a few quarters down the line after they report huge losses, which would get the board/CxO fired. Therefore, they need to do something wherein this new hardware division actually shows revenue, if not profit. Therefore, they will think "We need to manufacture hardware that people will buy. People like Apple, but we can't make iOS devices. Hmm. If only there were an open platform which has lots of apps and is successful... hey, what about Android!"
It seems simple and logical to me and it's what I would do with WP (after firing Belfiore in public) if I were a MSFT decision maker. Businesses care little for loyalty and whatnot.
The final equation boils down to something like this: WP has currently 3-4% of global marketshare. If Android Nokia devices could capture even 7-10% of the market (which I think they will) that is a net win for MS. Not so much for fanboys, but omelettes, eggs, etc.