> I would not write a wiki app in it, but certainly the next Apache or Nginx replacement.
I wouldn't. Nondeterministic garbage collection in a web server like nginx (as opposed to an application web server like Jetty) makes me very nervous. The HTTP (or pick-your-other-TCP-protocol) lifecycle is well-understood enough that you should be able to handle your own memory management.
There are lots of things in Go I like, but for me they're coupled with questionable abstractions that make it difficult to rationalize over C++.