Hopefully some day they can expand to support all the functionality added onto CPAN, like PAUSE, cpantesters, BackPAN, CPANTS, Test::*, TAP, CPANPLUS, local::lib, cpancover, cpanratings, cpanminus, Perlbrew, Carton, Pinto, minicpan, Metacpan, CPAN RT, AnnoCPAN, etc. You can go right now and find the test results of building whatever module you want on whatever perl you want on whatever platform you want, find ratings and user comments, and see general quality ratings of a module distribution's construction.

The only problem I have with CPAN is its lack of a past. You can't just re-download some module from CPAN you had installed a year ago, because it got removed from CPAN and now it's on BackPAN, so now you have to cobble together some scripts to download all the correct dependencies from BackPAN, and use Perlbrew to get the right perl version + core, and use Pinto to maintain your archive of old modules for the branch/release of your application that it matches. Maybe this is a problem that every language's library repositories have, but it's annoying that there isn't a CPAN standard for "install only the dependencies of module X at the time Module X was released".