The previous post makes a good point. I after all already have an IDE that is lovingly tuned to my usage case with innumerable quirks and tweaks I find useful. I'm lead to believe there are hackers out there who don't use Emacs who I might want to collaborate with. They likely have their own favourite IDE/editor which works for them.
Really what you need is an open API for communicating with such cloud-like collaboration services that can be plugged into any number of editors. I'm sure a web front end will also be useful for those quick edit sessions. In the mean time what can I use for C-x f collab:/server/project/file?