Jon Udell - How do you design a remixable Web application?:

"A website that wants to be remixable will deliver content as XML and behavior as script. These aspects can be, and will be, combined server-side for Web 1.0 clients, but Web 2.0 clients will increasingly be able to do this processing for themselves. So there will be two ways to remix: by intercepting the server-side combination of XML content and scripted behavior, or by recombining on the client."