This idea goes back a long way, to my pre-Jabber days (!) when I was experimenting with getting my business applications to write messages to IRC channels and writing various IRC bots to listen out for and act upon specific messages (carrying out simple processes, relaying messages to further channels, and so on).
Just as HTTP-GET function call based apps — such as the ‘open wire service’ Meerkat, and other RESTian applications (‘RESTful’ may twang too many antennae ;-) — are both human and machine friendly, so is simple publish/subscribe via spaces. Just as people (with browsers & URL lines), and applications (with HTTP libraries) can get at HTTP-GET based information, so people (with Jabber groupchat clients), and applications (with Jabber libraries), can get at published data in open spaces such as Jabber rooms.
The plugin is very raw, as I’ve just written it tonight and done some minimal testing using my current feedlist.