Google: nah.
Honestly I shouldn't even suggest that, it will probably get google groups closed in a whim.
I have trouble imagining what a vim/emacs user group would be: either some sort of nonstop abusive flamewar or some kind of kumbaya group you can only join if you can prove you're on a dangerously high dose of lithium.
Also groups that trade baking recipes in org-mode format plus vim macros so they can share the fun.
Public groups is just one aspect google groups, probably not the most important use case.
That's a great point, and I would add that when Google launched Google Groups, there was this widespread concern that Google would abuse it to kill Usenet and force users to switch to its own walled garden.
Since then, Google already tried and failed to launch a couple of social networks, but Usenet is still around.