Yep, perl is part of OS X, thank god. If you'd like to know where your perl distribution resides, type
$ which perl
I'll save you time. It's installed in /usr/bin/perl, the standard location for perl.
I've written and run perl scripts and it works fine, of course. For now, the only problem that I can see, is the lack of xemacs. Although xemacs has been carbonized (see osxfaq.com), I haven't been able to get any of the debugging and formatting tools to work. writing complex scripts in something like vi just doesn't cut it.