Yeah, you're probably right. Am not seeing any reasonable references to it in a quick search.

http://www.google.com/notaurl - is also served via sffe.

http://josephscott.org/archives/2010/11/user-agent-sniffing-... - as are the js libraries they serve.

http://news.ycombinator.com/item?id=2280319 - @dmaz seems to think it's google's static resource server.