I am very excited about XAML.  I have been using MyXaml in a product for a while and I know there is Xamalon and I wish them well.  I think there will be a market for XAML on Windows Forms 1.1.  Avalon will only be for Windows Forms 2.0.  I am most excited about XAML for 2 reasons.  First, skinning an application should be much simpler.  Second, related to number one, allowing a user to re-arrange the controls on a form should be much simpler.  Its amazing how web development and windows development are converging.  ASP.NET’s server-side controls make web development much more like VB6 forms.  Now Avalon is making Windows Forms more like ASPX pages.  I like that because there are lots of developers who can make a good UI and lay it out pretty well and the control interaction is good.  But then there is a breed of developer who is gifted in choosing just the right colors and moving the controls even just a few pixels one way or the other and Voila it is 100% better.  With Avalon (like ASPX) just send the layout file to a developer who specializes in UI’s.  But most of all I am waiting for a product similar to DotNetNuke (DNN) or Sharepoint where a portal is more viable.  I want users to be able to rearrange the UI in a graphical way like Sharepoint.  I want User Controls to be more useful and pluggable like in DNN.  This will greatly enhance thick client development.