I think Richards' CL's were submitted to main Go repo before Go 1.6 and are now in 1.7 dev branch (tip). I believe I first saw the announcement on godev list. as a Go user, it is a good way of keeping up with the fast-paced development; e.g. IBM's linux/s390x port went in today!
I usually keep one environment in sync with the latest sources and try out the new features that affect me the most, but I don't think there's anything special about that.
Next to try on Plan 9: build a linux/s390x binary and find a machine to run it on :)