Microsoft did take over Nokia much later than the N900. In fact, Nokia lost value after iPhone showed, and it is only when MS could take over it. And the Android is a side effect of the fact that the .NET was not ready to run existing phones, and Microsoft decided to release the WindowsPhone as non-Nokia branded one.

My BSD statement stays, though, MS did some very good work with the WinPhones, and in fact they were super snappy and useful, very close to what iPhones were at the time. And let's not forget, that the flat looks of (not sure which macos) was directly influenced by these winphones...