Amen. I’d love to see a rebrand to Rakudo and Pumpkin, where the latter is Perl5 plus some long-overdue backwards incompatible changes, but also 99% compatible.
I'm not really sure what you want in terms of backcompat breaking changes. I feel like if you do enough to make Perl 5 modern, you end up with Perl 6, but different. Once you add real Unicode support and a MOP and concurrency, you've reinvented more than half of Rakudo. It should be called Perl 7, so we can have yet another version.
I think there is this idea that you could graft the Perl 6 object model onto Perl 5 but keep the things people like about 5 (that it's implemented in C and installs more like a normal Unix/Linux tool that we are all familiar with). This would open the door for CPAN modules that exploit the cleaner and more modern object model like we have with Python and Ruby. Which would in turn allow Perl to be more in line with what people expect from a modern tool, combining the best of the old and best of the new.
I think if you start with the state of CPAN and work the problem in reverse you might see what people are wanting.