I have a copy of Perl installed as a local user, which I try to keep in sync with my main servers. It would be useful if the emerge system were to check Perl dependencies by actual package, rather than simple ebuild package management ie, if they were to try <code> perl -MCoffee::Latte || ebuild perl-apps/Coffee::Latte </code>
Someday, in the near but distant future, g-cpan will be rewritten and fully integrated with portage and such a feat will be possible. Unfortunately, we can't do that yet.