Well, it actually appears to be a KDE feature. As I can print to PDF from most apps that use the KDE envoirpnment.
In KDE 3, The Configurator has options to define the default printing... well, "Print as PDF" is an option.
Dunno, if we can in GNOME... haven't looked. Been to enthralled with KDE as of late. KDE 3 just feels... well umm... gosh... better. Can't quite put my finger on it, it just IS better, no quantitative reasoning.