Hi Steve. Have you looked at Brad Abrams demonstration of the current RIA Services approach (http://blogs.msdn.com/brada/archive/2009/07/14/business-apps-example-for-silverlight-3-rtm-and-net-ria-services-july-update-part-4-seo-export-to-excel-and-out-of-browser.aspx
As I recall, there is actually very little here that is specific to RIA Services. It's pretty much Silverlight with a little RIAS thrown in; you should be able to substitute DevForce without much trouble. That was my impression when I looked at it months ago. I didn't have a compelling need for SEO so I moved on.
I'm curious about the context of your question. Happy to talk to you after you've taken a peek at Brad's demo and have refined your thoughts / questions about how DevForce could fit in.