(a) the existing installation is not detected with a bailout option ("blah blah already installed blah blah do you want to continue?") This should probably wait until there is a distutils registry of installed modules.
Is this in the works?
No, I'm not aware of any activity. However, it's on the todo list. Here is a comment from a message 'Tasks arising from IPC9' by Andrew Kuchling, dated 3/10/2001: 3) Other Distutils changes would be to design and create a package database, and implement an uninstall command. The 'sdist' command would also grow an --upload or --register option that would automatically submit the package to the catalog (but first we'd need to finalize how that should be done). IIRC, Andrew said this would probably require a PEP. Thomas