Worth listening - I have enormous respect for Peter and the work that the XMPP community has accomplished. We tend to put XMPP in a box (yet another protocol for instant messaging that also happens to handle presence). That's unfortunate. XMPP has a diverse range of possible applications - for instance, there's a lot of talk lately about the synergy between XMPP and lifestream tools (e.g., Twitter) as well as a means to augment Atom/Atom Pub systems. I have no qualm with SIP at all but remain convinced that SIMPLE is fundamentally flawed, is being used by vendor to advance their own agendas, and should not the one-basket-for-all-eggs direction pursued by the industry when it comes to approaching "presence" in a broader sense. SIMPLE will have it's role, but XMPP should not defacto be dismissed as an option.
Peter Saint-Andre is Executive Director of the XMPP Standards Foundation. XMPP (formerly known as Jabber) is today's leading instant messaging protocol. As Skype users know well, IM is nothing without simple presence signaling. Lee and Peter talked about emerging presence.