http://www.google.com/trends?q=perl The downwards trend seems to be flattening off, maybe "it's losing popularity at a slower rate" would have been more accurate? Seems pretty cruel teaching undergrads Perl when they could learn Python.
http://www.google.com/trends?q=perl,+python,+ruby&ctab=0...
I wouldn't have guessed they'd each surpassed Perl around 2007.
Edit: Also, despite a steady decline, watch Java dwarf them all: