Yesterday I ran across an extremely exciting fact: AOL is now running an XMPP server at xmpp.oscar.aol.com that accepts logins from AIM/ICQ accounts and can talk with AIM/ICQ contacts. This means that there's suddenly 53,000,000 more people (according to 2006 numbers from Neilsen/Netratings) that are accessible from XMPP. I've made a brief timeline of important events in XMPP's growth.
1999: Creation of XMPP
2003: Jive Software releases the first version of Jive Messenger
2003: XMPP passes ICQ in number of users
2004: IETF approves XMPP as an official standard
2004: Google Talk released, dramatically increasing XMPP's market reach
2005: Apple announces XMPP support in iChat and Mac OS X server
2006: LiveJournal adds XMPP support, creating 14 million XMPP accounts in the process
2008: AOL creates an XMPP-OSCAR bridging server, adding another 50 million or so users accessible via XMPP
As you can see, over the last four years XMPP has gone from a relatively tiny force to a huge player in the IM world. Now all we need is for Microsoft, Yahoo, and QQ to follow suit and most IM users will be able to talk to each other without the hassle of creating accounts on each service and using lots of different programs (or multi-protocol programs) to connect to them.
I'm extremely excited about the possibilities of this, although a little worried about the lack of public acknowledgement from AOL. Hopefully they will continue to move forward with this, and make an announcement in the near future.