>Other than Google has a bad history with 1) Putting products in beta and then killing them (http://fox.wikis.com/wc.dll?Wiki~GoogleBandWagon~WIN_COM_API)

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.

> and 2) Making massive changes to languages (There will be no upgrade path from Angular 1 to Angular 2), I can't think of any reason.

Maybe they have learned their lesson here,there are lots of mentions about how future versions will remain backwardly compatible.