I made a downloadable release available at http://springutils.fluffnstuff.org/downloads which should serve as a base for further discussions.
Is this going anywhere, I only build windows applications so I'm very interested.
We are actually just beginning work on a new Spring.NET Extensions project and a forum has been setup here.
I'd encourage you to post your questions, thoughts, suggestions, etc. in this new WPF Extension-specific forum so that the lead for this extension project can engage you in a dialog about your efforts and interests in this area.
Launching this new extension project is the first step in developing a robust support for WPF into Spring.NET and so we'd very much welcome your input and insight into the best ways for Spring.NET to support and integrate with WPF.