Obviously not everyone likes what we are doing with XAML... Gerald Bauer says "Evidently working together with others to build a rich internet for everyone wasn't on the agenda."

And he also posted a mini-play:

"Act I: Ellen and Ian discuss Microsoft's Longhorn
Markup Language (XAML):

Ellen:  look at that xaml page. it's just ridiculous
Ian: you mean how much it's like XUL?
Ellen: yeah
        except that they use C# instead of js
        so if you want interactivity, it has to be
compiled
Ian: right.
jeez. wow.
could that be a bigger rip-off?
Ellen: it's stunning"

Obviously I need to look at XUL more - frankly I never have seen the XUL syntax or used it. I found the spec for XUL 1.0 over at Mozilla and saw some of the markup there...

How do I create a new custom binary behavior using XUL? I understand that in IE I am able to implement IElementBehavior and then I can create a new custom element, but I'm wondering how this works in XUL?

XAML is a simple langauge that binds to CLR objects - there is no set of "intrinsic" objects in XAML, everything is based on CLR metadata for types.

Anyway, obviously everyone will have their different views, should be a fun couple years while we all try to make progress on this stuff...