My current approach - I'm currently on Fedora 10, but the question is actually the same for all Linux distros - is to use the distro's install/update mechanism, then install/update CPAN and update/upgrade everything that's newer on CPAN.

I've never tried that although I was very tempted.

An interesting point was made by chromatic on Modern Perl Books blog:

OS vendors who package and distribute Perl and use it for core utilities should install their core libraries in a specific directory accessible only by their core utilities and they should configure Perl to install modules from the CPAN in another directory where their utilities do not look.

That is, if you distribute Perl as part of an OS or distribution, and you distribute Perl utilities which the system needs to function, you must pay attention to specific library versions and ensure that the proper library versions are available, even if users install newer versions from the CPAN.

Do OS vendors do so? Unless I don't understand above quote, keeping /usr/local at the beginning of @INC for e.g. scripts in /usr/sbin is "broken-CPAN-update-prone".

$ sudo perl -V
  @INC:
    /etc/perl
    /usr/local/lib/perl/5.10.0
    /usr/local/share/perl/5.10.0
    /usr/lib/perl5
    /usr/share/perl5
    /usr/lib/perl/5.10
    /usr/share/perl/5.10
    /usr/local/lib/site_perl
    .
[download]