Murray have blogged about the UDS, primarily from a Gnome perspective
Read about it at the blog:
Canonical (or Ubuntu, or even Google, not sure) sponsored travel and accommodation for upstream participants, including several people from GNOME and associated projects. Now thats really working with upstream. We were new to the Ubuntu Summit way of doing things but figured it out quickly. I think we all felt we should be doing more to justify our presence, but hopefully we provided at least some valuable input and advice, and some of us even started implementating specifications. But most of the specifications being considered were lower down in the system, dealing with things such as drivers, devices, X, etc.