in reply to Are there any major Perl issues with Mac OS X Lion?
I've not yet used Lion, but in all previous versions of OS X ... yes, you need to install the dev tools; there are no issues with the CPAN toolchain or with the vast majority of modules (you say you're coming from Windows, so while you will still run into some non-portable code, you will have fewer problems on OS X than you're used to); obviously most stuff with a platform-specific namespace won't work; in general you can assume that it's a normal Unixy system.
Some Mac::* stuff is for the obsolete pre-OS X rubbish, but it's normally obvious from the docs which is which. That said, I doubt you'll ever need to use any Mac::* stuff directly. I certainly haven't.