For me what will happen is that Microsoft will claim in the future that Linux is very good because it uses part of Microsoft technologies. It will sound to the noob as it was Microsoft that made Linux great. I even go further:
Why Linux is so great mr. Balmer?
-Linux employs one of our core technologies, .NET, a robust and feature rich API that developers developers developers love so much. Thanks to our efforts Linux is now gaining momentum. Next year we plan to release Microsoft Linux XP...
Then the world implodes. *mooB*