It seems the communication between the perl porters and CPAN module authors on one side and the distributors of these packages on the other is, well, lacking.
To slightly improve the situation I talked a bit with the Perl packagers of Debian and Fedora that resulted in a wish list from their part. I have posted it on the Perl 5 wiki under
CPAN packaging
I also started to create a list of the other perl and CPAN distributors so it will be easier to ask them as well.
I need your help to create a comprehensive list of these, so if you know who is responsible for the native perl and/or CPAN packages in your favorite operating system, please post it under Distributions
