I'll probably be stoned for saying this here -- learn lots of languages.

Over specialization can shoot you in the foot.

In the middle ages, you'd apprentice until you learned the basics, and then you'd become a journeyman -- you'd travel around, trying to learn from different masters, until you had the skills so the guild would consider you to be a master yourself.

You can learn a lot from taking the time to look around, because sometimes looking at things in different ways can help you learn, if you didn't quite grasp the concept the first time around. (and you might've thought you did, but realize later that you didn't). I've had that happen more than once, when the light suddenly hits ... (I still remember when I finally got object inheritance ... not just using it, but really understood what I was doing with it... and it was from coding LPC).

Even if you don't ever use a language again, you'll find that you start to think about the problems differently -- I took a college class on 68k assembler one summer for the hell of it. I've never written another line of assembly again in my life, but it helps me think about the problem differently when I'm trying to optimize my code.

It also helps you make more informed choices ... it's one thing to try to argue to a group that the project should be done in Perl, when that's the only language you know -- if you know other languages, you can give good reasons why it's better than some other option given the proposed project.

As for Perl ... it'll still be here 5-10 years down the road, so long as we don't manage to blow up the planet by then. (after all, COBOL's still kicking around) It fits a niche -- sure, it might not be the fastest in execution speed, but it saves me work (in the long run...maybe not in the short run, when I find I've got some ambiguous code), and it's a hell of a lot more portable than most other languages.