For my current job, for example, Perl wasn't mentioned any time before I was hired, but nevertheless I use it frequently, both for munging text and maintaining CGI sites.
I still find that I can do twice as much with half as much code with perl. And I don't have to jump through any hoops to see my regexes do what I intend them to.
As far as general day to day data munging....this is what perl is for. I believe that the web popularity of perl was a side issue for the hard core perl gurus. (no claim of perl guruism)
Practical Extraction and Reporting Language.
This is exactly what I still use perl for. Just now it's mostly scouring websites with LWP and extracting their content, then reporting it back to me.
Its the one tool in my "programmer's toolbox" I can fall back on when all else fails, and when I need to hack up something quick for the moment, or to write a script for administration or file manipulation that has to work in a heterogeneous environment.
Perl will decline somewhat on the web as more web-specific languages come and go, but it will never go away. It's too damn useful.
(It totally annoys the hoity-toity java programmers where I work that I've had to glue everything together with Perl on the back end... because it works, it's bulletproof, and I can hack out the needed utility/script in an afternoon that would take a couple weeks to get through Development, QA, and Deployment.)