Don't like the way XAML works today? Have some ideas that you think will make it easier to work with or more robust? Well here's your chance to make yourself heard.
Personally, I think XAML has everyone confused as hell right now. Microsoft currently has it packaged as if it belongs solely to Avalon. This makes sense since this is the team within Microsoft who actually had a concrete use for it at first. However, as Don has demonstrated, it can also be used to write code that has no relation to Avalon technologies what-so-ever. The core, abstract concepts of XAML are really easy to understand if you take away the more concrete, complex, Avalon specific samples.
Personally, I think that XAML needs to be taken out from under the Avalon umbrella and packaged as a generic engine. Then the Avalon side of the story simply becomes one of re-use and specialization of that engine.