nice feature but Go is available online at http://ideone.com since several months
Also, it's running a _really_ old version of Go. (http://ideone.com/spBzw) It's at least 400 revisions out of date. We intend to keep the golang.org Playground up-to-date.
There have been language changes as recently as this week. Go moves fast (although it's unusual for existing code to break).