And the beauty is that a couple of code jockeys like Phil Torrone and his partner Sergio Zlobin can make it happen in a few days, using platforms (IM) and data structures (RSS) that already exist.

Source: John Battelle's Searchblog: What Happens When You Mashup RSS, IM, and Publishing Services?

For what it's worth: Building an RSS and Atom powered IM chatbot appears in Chapter 4, Adding Feeds to your Buddy List, in Hacking RSS and Atom—and it's even the screenshot featured on the back cover of the book. It's got lots of room for improvement, but it does have what I think is a nice and simple conversational interface for subscribing and polling feeds.