It seems like this implementation requires a second communication channel in order to invite new users. That's interesting - and not too different from traditional IM.
Maybe this time next decade we'll still have email accounts, but they'll contain nothing but invitations to next-gen communication media? Oh, and spam.
It is basically a combination of real-time instant messaging (where each letter typed can be seen as it is typed), email, and collaborative document editing all in one. You can have as many people typing and editing at the same time as you want - which can be very entertaining actually among curious hackers goofing off. The key though is that each conversation is contained in a single object, the wave, and you can add as many participants to that conversation as you like, including "synthetic" participants or robots. Right now robots have to run off Google's app engine and you can write them in either python or java (we chose clojure on top of the JVM). You can also add "gadgets" to the wave, which are client side objects that all participants can see (in the same state) and when the state is changed, all participants see that change as well. Additionally, the wave is tracked temporally, so that you can "replay" the conversation as it occured.
So what we are doing is using a Robot to transfer information between our webapp and Wave and inserting gadgets to give views back into our webapp, etc. Robots are a very powerful idea.
A wave isn't a flow of synchronous text (or asynchronous posts, for that matter) - it's a standing unit of editable text + widgets + threaded comments. Sort of live-wiki-ish.
You could do the same with the logging bot if it supported line-editing command messages, then just put a GUI on top that translated the visual-editing commands to line-editing semantics. I'm not saying any IRC server/network I've ever seen does this now, but it's not out of the plausibility range and far easier, I think, than pushing an entirely new protocol. But I digress: perhaps I should just set it up myself and see if it really can be done.
gmail meets twitter meets gtalk meets wiki meets pingback - with a twist that you can have web pages a client to wave so you can show there your feeds too and that typing can be seen real time on the other, recipient, side. Oh and add to that that there can be multiple participants. Participants can be robots too, and you can mash up all of that into multiuser game kind of experiences.
