I do the majority of my paid development work in Perl. Web applications, intranets, database integration merging, etc.

There is a fair bit of Perl out there running commercial applications, it's just that it tends to be infrastructure and server-side stuff so is not particularly visible.

That said I do write code in other languages, and so should you (if you don't mind a bit of friendly advice :-)

Over the last fifteen years I've seen the language-of-choice go from Lisp to C to C++ to Java. Who knows what's next (maybe Perl6 :-)

I've lost count of the languages I've coded in over the years - and I still try and learn a new language/skill a year (Ruby this year - most funky).

If you just have one skill you're dooming yourself, because I can guarantee that at some point in the none-to-distant future you'll see that skill disappear into the mists of time. Be flexible. Know more.