Look at the number of pull requests being made by the community and how many changes are accepted back into the codebase. That will give you a good idea of the ability of the community to carry it forward.

>I think it may have passed that particular stage now, it is already being used internally by Google and others in production. Thats not to say they definitely won't forget to develop it any further and leave it to die, but if they do it is Open Source so the Go community could take over future development.