David Betz posts a nice video demo of some basic Databinding in XAML.
Few notes that I took about the demo:
1) The color capture of the video didn't make the gradient look very good. Very banded. Yes, it wasn't going to look much prettier...but at least the gradient will look a bit smoother.
2) David was using a build previous to the Feb CTP...one major difference in Feb CTP would be that you wouldn't need the Mapping PI that he used...instead you would just use:
3) David hacks on his object to make it available declaratively. He adds a property. (note, he could have used attribute syntax for that property...instead of Property Element syntax like he does). In order to make an object be expressable in XAML, do the following:
a) make it have a default constructor.
b) make its state settable via properties only.
For more on WPF databinding, I can recommend:
Namita Gupta's PDC talk (September 2005)
Beatriz Costa - a WPF team member blogging on Databinding.