So they can wipe out the competition with the successor of WP7, like they did with the successor of Vista?
Sounds like a good strategy to me!
Has it? I think that Microsoft is too busy with its own forced obsolescence initiative to worry about its competitors. After all, it has been trying to kill Windows XP for a few years now as part of it and that has not worked very well. In the mean time,
Mac OS X has been siphoning significant marketshare from Windows and other UNIX-like operating systems have been growing in popularity too, although they have been growing at a slower rate than Mac OS X.