Well, that's a bit of an exaggeration. When I left Yahoo Europe in 2005, there was still Perl all over the place both in Europe and the US at least. I managed the Yahoo Europe billing system, and that was mostly Perl on the backend, for example.
[small world, btw., courtesy of some minor profile-stalking: I interviewed with Ed about a position a few years back; your service looks interesting - I have a client that might be interested]