Well, as of Windows Vista, this still wasn’t really possible. Sure, there were hacks that allowed you to remove certain parts of IE, but they generally ended up breaking something else on your system.
However, in newer builds of the beta operating system Windows 7, Internet Explorer has been added to the “Add or Remove Windows Components” dialog, so it can be successfully uninstalled without killing your Windows system. I first read the news in a news article on Yahoo!, though the find was apparently actually made by two gentlemen named Bryant and Chris and were initially posted on each of their blogs.
While this sounds like good news, I just don’t see it making any kind of major dent in IE usage. After all, as long as IE continues to be the browser that comes pre-installed on Windows, it’s going to dominate and very few people are going to bother removing it.