Regarding 1) and 2), that's why the author suggests XMPP. It would mean you can aggregate Google and Facebook chat in the browser, have your existing contacts l

Regarding 1) and 2), that's why the author suggests XMPP. It would mean you can aggregate Google and Facebook chat in the browser, have your existing contacts lists, etc. Of course, users of Facebook chat can't add arbitrary XMPP contacts to their friends list, but that's a different problem.