Thanks for your feedback. I try to answer your questions as good as I can.
1) PRISM has the strategy to support all platforms WPF, Silverlight and Phone 7. It comes with lot libraries (e.g. Unity, Enterprise Library) and the framework isn’t that small.
A strategic goal of WAF is to stay “lightweight”. Furthermore, I focus on one platform, WPF only. The sample applications are a key part of the framework. Every feature should be used by one of the sample applications at least
and the samples provide a lot best practices in the field of WPF developing.
2) WAF doesn’t provide direct support for extensibility. But when you are using MEF then it is quite simple to enable extensibility. Here you can use the concepts shown in PRISM as well.
3) You should be able to mix the module/modulemanager classes from PRISM with WAF without any problems.
4) A service is just a simple .net class that might implement the INotifyPropertyChanged interface if necessary.
5) I have lot ideas for new features but I won’t make them public now. Sorry.