I read an interesting article (no doubt written by someone at IBM) that shipments of IBM 370 architecture machines has never slowed down (now called S/390). I remember writing PL/1, COBOL and BAL for those giant fossils. I also remember seeing an emulation running on a 486 laptop that ran faster than the original machine.
Somehow I'm not buying this. I know there's a "y2k" play here somewhere but I don't quite see it yet.