Rob Relyea (MS Avalon team) compares XAML to html+css in response to a DevX column. He covers:
- inline formatting
- style sheets
- style and property inheritance (supported even in Windows Forms)
The column, by Nigel McFarlane, is much more comprehensive, covering about 100 XAML tags and comparing them to XHTML, XUL and SVG. Very interesting read.