> So if i get it right, the way "Google" sees the future, there is Go at the server side and Dart at client side (which is in fact JS). Am I wrong?
Yes, you are, in fact, wrong. Google doesn't have so narrow a vision. Dart is server and client side (the native VM is, aside from a for-testing-only build, server-side only now.) But the client side isn't just Dart (or JS, in which Google has also invested heavily), its also C/C++, and other languages, hence PNaCl, which also just went into general release.
And, sure, Go is a server-side language that Google is putting energy into, but so is Dart. And I doubt their vision ends there, those are just a couple of the more visible active fronts.
> I would expect Google, or at least, a team at Google, to take over NodeJS which is based on their V8 and expand it to universal server client language and libs.
The existing NodeJS team is doing enough for server-side JS-on-V8, and its open source -- Google could throw more resources, but its probably not the best bang-for-their buck in terms of developing new technologies that might improve the options for the things Google is concerned about. Doing what other people aren't doing is a bigger win.
> Let alone I see no effort on their side bringing any of those language into the native world of Android
I've seen quite a bit about Dart on Android (though I think there are issues with building the current distribution.) Less on Go.