Maybe I'm getting paranoid. Bear with me for a minute or two.
What if this ("Getting the malware to the right person's machine will be a bit of a trial" says TheReg) was this ("eliminates all previously discussed security vulnerabilities affecting IE 5.5 and IE 6")? Installing the browser patches is essential, of course, given the massive security holes otherwise. But if the patches were spyware, how would you ever know? If you're running a personal firewall (I like Tiny), the browser is probably your most trusted application.
Paranoia aside, it's time to spend more time using Opera (and the wonderful Galeon, of course).