Microsoft has a loooong history of partnering with companies only to undercut them..IBM and OS/2(which MS morphed into NT, then 2k, XP, Vista, Windows 7, *..etc etc etc)  Novell(which they used to develop Active Directory then cut the legs form under Novell).etc etc.  I found it interesting that a former Microsoft exec went to head Nokia and right after that Nokia is not only dumping Symbian but nearly totally shutting down it’s own R&D to bet the farm totally on Microsoft.  MS phone systems haven’t been market leaders..they’ve been followers and WP7 is no different.  If part 2 of this article is correct MS just bought their way into being able to make their own hardware.  If that’s correct Nokia’s market domination days are over.

Microsoft gutted Nokia and left them without a chance | SemiAccurate.