Rob Relyea writes about some changes that the Avalon team is considering to the XAML syntax. Scott and I got into some heated discussions with the team when we were first introduced to XAML at a VSIP lab.
I am glad they are thinking about changing the "*Bind" syntax to be more extensible. I see this as an area where ISVs can modify or improve property and data binding in XAML.
In addition, decoupling XAML from the presentation framework would help make it a reusable object graph persistence framework that we might be interested in for some future product scenarios we're thinking about.