Neat. My friends and I switched from ejabberd to Prosody[1], a Lua XMPP server; Lua is quite a bit easier to use than Erlang (unless you are already an Erlang grandwizard), so writing new plugins is a breeze with prosody. Of course, ejabberd already has a lot of plugins written, so lots of benefits there as well.

Good luck! Hosted xmpp could be executed really well.

[1] http://prosody.im/

What are you using for full-text search, anything unusual or just postgres built-in search?

I can also see nginx from http headers.

True. nginx as well.