The issue with Meego isn't it's technical merits, it's adoption by Nokia's best customers. WP7 is designed to integrate vertically into the enterprise technology stack - just as Android is designed to facilitate integration with Google's services in order to allow data mining and iOS is designed to sell Apple hardware. WP7 facilitates B2B sales for Nokia in a way which Meego probably never could.

For Nokia, WP7 almost certainly offers better potential globally in the high margin corporate smartphone market than the alternatives. Because of it's .NET capability one can implement some of the same objects on the phone the enterprise implements elsewhere, e.g. it's servers. While this is also possible with other approaches, there are not the same incentives for development tool providers to invest in the level of cross platform compatibility as the incentives which Microsoft has to do so.

Based on the evidence, it looks like Nokia evaluated the WP7 roadmap to be better than those created internally for Meego and Symbian, and given the IP uncertainty surrounding the JVM their reluctance to become just another Android phone manufacturer does make some sense.