Unfortunately there's no proper demo page :/ We're working on improving the docs (we know this is big issues atm).

There's an old version (from June) of Orbit at http://orbit.libp2p.io which you can try. Much has happened since and we're working on bringing the js-ipfs version Orbit back to a working state.

Re.Pubsub, I'm personally also very excited about it! :) The specs and general info are located here https://github.com/libp2p/pubsub. go-ipfs merged pubsub into master some time ago with this commit https://github.com/ipfs/go-ipfs/commit/e1c40dfa347e38bdc9812... and we're working to get it into js-ipfs here https://github.com/ipfs/js-ipfs/issues/530.