I'd absolutely miss map and grep. Those are the first two things that came to mind (and the most missed when I had to do Java). Following that, I'd put regexes, statement modifiers, the convenience of the data structures (Oh, sure you can malloc memory and build a dynamically sized array in C, but when the language does that for you, why would you want to try to build a hammer out of a rock and some a stick?), and many of the other things that make Perl Perl. The "TMTOWTDI" philosophy probably sums it up best, though.