Should an author be able to delete a currently-indexed distribution on the CPAN? Yes, without reservation or exception. Open source is free, and that freedom includes removing my consent for my name to be attached to a publication at any time.
However, we (the CPAN community) can do a lot of things after that to mitigate any damage. I wholeheartedly agree with transferring namespace permissions to something that the PAUSE admins control, so any random joe cannot claim the namespace and upload whatever he likes into it (this is an attack vector we must keep closed). We also need to be able to act quickly to publish something in its place so installations pulling directly from the CPAN do not break. I would suggest an email alert go out to the modules@ list (or another list, should this prove too noisy) providing notification that an indexed module is being deleted and de-indexed.
