One of the systems integrators that I work with (they do my HMI applications - operator interfaces for industrial automation systems) found that IE7 gums up their applications. IE7 got automatically installed on my system, however I was able to get back to IE6. Microsoft has really stepped in it, and I think Microsoft is going to wind up pissing off a lot of business users.
I was automatically updated too....and on alot of my pages I get 'run time -- do you want to debug errors'. So for those web pages, I use firefox.