There are a few pieces missing from the puzzle, though. Below are a few things I learned during a several (non-NDA) conversations I’ve had with people at MIX. Some of these issues have also been confirmed online.

• No Socket Class — Currently the only way to communicate is through Windows Communications Framework or pure HTTP calls. The practical implications are no chat or mail apps, limited multi-player communications.
• No Local Database — This is problematic. Storing data in a local database is essential, not only for applications that can work offline, but more importantly for regular applications to cache information, increase performance and reduce network traffic. Application vendors could include their own database engine (such as C# SqlLite) but if everyone starts doing this it will only create bloat, increase memory usage, and delay application startup.
• No In-App Purchase — This is no biggie, in my opinion. Aside from a few content-centric apps, the in-app purchase in the iPhone AppStore has only been used for semi-trial versions. The trial scenario is already supported by Windows Phone.
• No Copy & Paste — Call me superstitious, but I believe missing copy and paste in the initial version is a prerequisite for launching a successful mobile platform (look at Blackberry and iPhone vs. Newton and Palm Pre).
• No Component Class — The Component class lets you create non-visible components that use the Visual Studio designer to define relationships with other components, change properties, and quickly create event handlers, all without coding. It’s not essential but very nice to have if you’re interested in building reusable, easy to integrate components.
• No Component Licensing – The lack of a LicenseProvider class means there is no standard mechanism for component vendors to license their components. Third party components give Microsoft a huge competitive advantage over other platforms, and it would be a shame if this opportunity is wasted in the mobile platform.

I was told that the Windows 7 Phone project was started only a year ago. The team has made truly remarkable progress and it’s no surprise that there are a few pieces missing. Hopefully many of these issues will be addressed before the final release.

One more thing: The Windows Phone OS update mechanism will be driven by Microsoft, not the individual carriers or device manufacturers. This will allow new versions to be deployed very quickly and let the platform to evolve at a very rapid pace.