Wintellect have published this whitepaper on CodePlex on the differences between WPF and Silverlight. I haven’t read it all myself yet as it’s reasonably meaty but from what I’ve seen it’s a very valuable resource to have to hand if you’re working with both environments.
Some of the items in the paper are illustrated by demos from my “Beyond Silverlight with WPF” talk at DevDays Holland the other week – you can find the materials here.
It’s a difficult time to be writing a paper like this because Silverlight 3 is in beta and so there are various places in the doc where forthcoming functionality is highlighted with text like “This is a current WPF/Silverlight difference but will change in Silverlight 3”.
Hopefully people will grab the document, download it and feedback and make it an even better resource.