Is it possible, using GeoWebCache or some other software, to expose Bing Maps as a WMS endpoint? I'm trying to incorporate Bing Maps into custom built software. The software is designed to communicate with WMS web services. Being able to access Bing Maps (Google Maps or some other mapping API would also work) via WMS would be great, since it would require virtually no changes to our software.
I've noticed that GeoWebCache can communicate with Bing Maps, but it appears that its web service exposes the map using the same protocol as Bing itself.