They did. I believe they had to uninstall the previous version and delete a lot of leftover registry keys and files. Amazing how uninstalls never really uninstall the thing. Never understood the logic in that. I've seen companies (like HP and Kofax) have to make cleanup tools for their own software because the uninstalls don't actually remove everything. I wonder if they contract their installation components out to third parties that screw it up.
Yeah, Visual Studio is definitely the right candidate for a cleanup tool. I guess Microsoft learned their lesson. It's a shame every vendor doesn't put as much effort into cleaning up their crap as they put into the installer, but maybe they figure if you're removing it then they couldn't care any less about you.