I think the assumption that Nokia would make more money with Android is unsound.
IIRC, Microsoft give Nokia $250m a quarter as part of their agreement, that's guaranteed income they wouldn't get from Google. Also, Nokia would have a fight on their hands differentiating themselves in the already saturated Android market. That Microsoft money funded the development of the Lumia range, how would they fund and publicise new hardware if their first Android device failed?
I'm afraid Nokia had been circling the drain for quite some time before they made the agreement with Microsoft. Perhaps, if they had got on the Android bandwagon at the start, Nokia would have been in a stronger position now, but they were wedded to Symbian and missed the boat.
As for the difference, Windows Phone is an excellent operating system; more advanced than iOS and incomparably better than Android, which is wedded to Java, making it unreliable and insecure. Android is flawed in principle and cannot be fixed, even if Google data-mining stopped tomorrow.
What Windows Phone offers is extremely smooth and reliable operation in an interface which is a pleasure to use with high levels of security for the user. I can say with confidence there are no bad Windows Phone 8s, but that most Android devices are awful. I've helped too many Android users with their devices to hold any other opinion.
Believe me, the only reason Windows Phone has a small market share is that it was late to the party. If Microsoft had released it two years earlier, Android would have never taken off.
If you want a new device, choose a Windows Phone because Windows Phone is the best OS by far.