The client portions are definitely in the library, and as you point out the node-webrtc library is looking really promising for interop with server processes.
If you need any help with the POC that you are currently working on feel free to reach out and I'll see what I can do (I'm the main dev working on rtc.io at the moment). Also, the primary dev on the node-webrtc project (modeswitch) is super helpful so I'm sure he'd be happy to help out also.
Either twitter or github is a good way to get in touch with me - usename is DamonOehlman in both channels...
I have done a lot of work w/ WebRTC data channels recently and I am working on a POC for hosting one's own "page" (i.e. facebook-esque profile page) themselves. WebRTC I think is the best technology so far for the decentralization of internet data from hosted servers to users. It still requires some server side things such as signalling (the handshake), STUN servers (external IP discovery behind a network), and TURN servers (proxies for complicated networks). By packaging up those three things into a single server that can be easily deployed by someone you trust (i.e. some kind of regional "manager" of sorts) and having good software to display web content over WebRTC data channels, a neighborhood-level darknet of sorts will be very feasible for even non-technical users.
1 - https://github.com/js-platform/node-webrtc 2 - https://github.com/js-platform/node-webrtc/issues/42 3 - http://code.google.com/p/rfc5766-turn-server/