1. Absolutely. We have some examples of using MVP in the code, as well as Presentation Model (aka Model View ViewModel).
2. Pros compared to Acropolis: Prism is something that will actually ship, and soon. WPF Composite Client is Prism, Prism is just the code name, and that will probably go away when we ship and become something more formal and hard to say but that pleases
3. We designed Prism to be a lot less invasive than CAB, and have a sample of integrating it into Family.Show that we will be showing at TechEd. So you could incorporate Prism features into a CAB application without doing a full migration. In terms of removing
the existing CAB aspects and replacing them with Prism, that is going to be a lot harder because they are fundamentally different architectures and CAB is intertwined into your whole application (one of the things we made sure not to require in Prism).
4. Acropolis is officially on pause I believe. But the fact is that it will probably not be resurrected as Acropolis, but some of the ideas and features of Acropolis will be incorporated in whatever comes next. Acropolis got put on hold because there were
too many things that they were signed up to do, and they realized they could not ship all those features in any reasonable time frame. Prism was launched to help bridge the gap between now and whenever the product team can release something like Acropolis
but with more coherent requirements.
That is my perspective as a vendor working on the product anyway, with what I know and can say. :)
Hoper that helps.