Hope someone (not me!) starts working on a nvimclient (akin to emacsclient) soon.
I think the current goal is to let neovim instances to communicate p2p so that they transparently use the same session. Mostly because adding multi-tenancy to vim would be a living hell without adding much over that approach. Has been a while since I have read up on that, though.
As long as I can have multiple clients working on the same set of files, I don't care how it's implemented. :-)