For web dev (not game dev) what is Python in danger of losing to? Rails?
Ahem...
http://golang.org/pkg/html/template/
It doesn't have its own equivalent of RoR or Django yet because most of the batteries needed for web development are built-in.
It seems that the web.go authors thinks that Go's template language batteries are of the wrong size.
What you're looking for is Revel. http://robfig.github.com/revel/
A very comprehensive list of the organizations using Go; I think it's kept reasonably up to date, but new ones are popping up on the mailing list from time to time.
For example, not to long ago we had the maintainer of pool.ntp.org asking some questions as he was rewriting some of the infrastructure for the pool from Perl to Go.