Microsoft has published the details of
Silverlight at MIX07. Apparently, this is going to be huge!
You can get an overview of what's in the box for developers by taking a look at the
developer reference poster.
It's interesting to note that the supported languages are C#, VB, JScript, IronPython, VB10 (soon), IronRuby (soon). It's funny to see that they use "soon" for VB 10 (VBx), while VB 9.0 is still not ready...
LINQ is supported by Silverlight, but support for LINQ to XML is coming
soon. Microsoft's XML Team has a word about this in
this blog post.