The Current State of Web Application Worms

Remeber the most recent Yahoo! Mail's XSS vulnerabilities, or the MySpace worm? I just read through a well written summary on Web Application Worms by Jeremiah Grossman, from WhiteHat Security, "Cross-Site Scripting Worms and Viruses - The Impending Threat and the Best Defense", an excerpt :"Samy, the author of the worm, was on a mission to be famous, and as such the payload was relatively benign