As you can see from Peter's comment on my previous post, the XMPP integration is really cool. However, it is also something that one has to experience to really understand.
I added the app to the chat window in my gmail account. The app instantly appeared as being online. I typed in a few messages and they either controlled windows, or wrote to the transcript.
Now, clearly this is not some huge theoretical breakthrough in computer science, but for end users this is amazing. I could build a simple web site for e.g. brainstorming ideas, and ask people to add the app to their buddy list. I could broadcast a message from the app, asking for ideas about xyz, and moments later their responses would come straight back into the app. From there it would be trivially simple to split them off, write them to a google spreadsheet etc.etc.
What this is doing is putting some really powerful collaboration tools in the hands of people who really don't need to know much about programming at all. Fantastic :-)