I second the recommendation of perlbrew. It makes it very easy to switch between different versions of perl, and avoiding the system perl is always good idea - especially if you want to install cpan modules.
For example, in order to get Padre (http://padre.perlide.org/) running on Mac OS X Snow Leopard I needed to install a 32-bit perl (perhaps 64-bit will work OK in the future). Perlbrew combined with the instructions found at http://wildperl.com/2011/07/padre-on-osx-dmg-now-on-leopard-snow-leopard-and-lion/ made it fairly painless.