Smart Client using Swixml

Hi
I am a part of the team, looking to migrate our companies web client
to smart client. To accomplish this we are looking at a bunch of new
technologies and libraries. I have a few questions regarding Swixml
and would really appreciate your feedback.
1. Does SwiXML follow the XUL, propsed by Mozilla or any other sort of
standard XML schema. I am aware XUL is still not a W3C standard. Just
want to know is there any specific XML schema, which Swixml is using.

2. Is there any proposal/exisiting tools to transform HTML to XUL (XML
used by Swixml).

3. Are there any ideas about extending XUL to cover data bindings(is
JDNC in picture) and also may be a metadata driven actions framework?

4. Any thoughts on building a tool/visual designer to generate XUL?

Please share if you have opnions/experiences regarding smart client
technologies. Currently I am looking at Swing/WebStart kind of a solution.

Thanks for your time.
Vineet