I would argue that it is not a place to manage applications, but it should have been. You can download apps and update them, and yeah there is some tracking of what you have downloaded, but I think they should have included an uninstaller. Hopefully this will come with Lion so that users can install, update and uninstall via the App Store without needing to ever visit the applications folder. this will make life very simple for the non techies out there. I always thought it was a shame folders existed in the Applications stack, it got a bit of a fix in SL, but hopefully Launchpad will fix all that.