Hi there, I've never used wpf or xaml, but I'm assuming you have? It looks like you might need to convert to svg or some type of text-based vector file. This is strictly based on reviewing microsoft's description of WPF and XAML. In this case, you will be making code to work with WPF since XAML is just a markup language like XML. I could also be way wrong. Here's where I found the basic info: http://msdn.microsoft.com/en-us/library/ms754130(v=vs.110).aspx
It looks like this could be used to make mobile, tablet, and other types of UIs, but I could be wrong. I'd suggest working within developer guidelines for the UI (assuming you're part of a team) and stick with the "standard" web sizing (ie: 4x3 sizes like 640x480 which are standard for most mobile devices and computers), keep snapping to whole pixels (WPF will do mid-pixel renders, but you get fuzzy lines), make sure to check art by testing and loading on mobile, stick with the "web safe" color palette and you might want to keep individual buttons and display areas on their own layers in case you need to separate it all out later for animations, layout changes, etc. might be easier to develop in flash instead of illustrator, too.