It all depends on what you are testing and how you are testing it. Perl can be good for gluing application modules together, certain types of automated testing, working with results files and even manipulating manual test scripts. And you might have a better understanding of what's happening underneath what the program shows you so you can help the programmers debug.

Being a tester should also be good for your software writing skills. When you write software, you will automatically think about boundary conditons and logic paths. If you're like me, even that might not help :) but I might be worse if I hadn't had any software testing training or experience.