is a fun read. I'm not really for or against people making up buzzwords, but a common language is always useful to aid understanding, and to me Ajax (if you're aware of it) does communicate more than his suggested "instead of Ajax, 'XML and script'"... (and Robert Scoble agrees)
Anyway, I was specifically researching information about using XmlHttpRequest ? after reading about an XmlHttpValidator for ASP.NET and Script Callbacks.
Finally - here's a collection of related sample stuff:
Presentation slides on 'Chubby Clients' by Anders Noras, info on XMLHttpRequest & Ajax-Based Applications
and an ASP.NET example from 2002, long before the 'Ajax' tag was invented!