[a3_nm]

> Is there anyone else of any consequence out there who is building these sorts of messaging apps on top of XMPP?

I use XMPP to talk with Google Talk users from an XMPP account hosted on my own server. I will be annoyed if Google users are driven away from Google Talk to something that I cannot interact with unless I use a Google account.

[npsimons]

Same here; and it's not like it's hard. If you're running a web server and/or DNS, it's as easy as 'apt-get install ejabberd', tweak some well documented settings in the config file, add a few lines to the DNS config, and bam! I'm talking to my friends on GTalk via my own private XMPP server.