I think you are selling yourself short. I came into WPF about 4 months ago, and believe me this framework consists of several paradigm changes (retained graphics, dependency properties, attached properties, etc, etc. ).
I would argue that Wpf IS Xaml, and that Xaml is not a pretty coating ontop of Wpf. Look at the current programming model for Silverlight. To do anything really sophisticated you must use InitializeFromXaml(). If you check out Petzold's book you will notice that he reimplements the examples from the first have in Xaml - and what is notable? The Xaml is more concise, shorter. It simply takes more raw C# to create the equivalent effect than with Xaml. Wpf is built around Xaml, Xaml wasn't added as a layer on top of Wpf later. Why is Xaml compiled into the assembly as baml, rather than the compiler just generating C# and generating IL from that? It is evident from the design that the declarative model is CORE with Wpf, not an afterthought.
Rob
Sells and Anderson's book eh?
I think you mean Chris Anderson's book with the forewords by Chris Sells and Don Box.
Not to be confused with the forthcoming 2nd edition of Programming WPF, which is by Ian Griffiths (me) and Chris Sells, with forewords by Chris Anderson and Don Box.