heh. I had a customer that was a lawyer. She was running an old Windows 98 machine. She needed to use some court recording software that the state and local governments used, and the latest version would no longer run on Windows 98. (And, of course, the courts required the latest version.)
So she bought a brand-new computer.
In February of last year.
Which came with Vista.
Which wouldn't run the software.
Six of one, half a dozen of the other. Either way, you still lose.
I have also had a customer that did upgrade from an old beige Mac to a (MDD!) G4, and ran into that very problem. Serial printer, SCSI scanner, failed to work. Luckily she had at least bought a Cinema Display to go with the new computer. (At least the old monitors work on a new computer with an adapter. I have used an ancient 14" "Apple Macintosh Color Display" on my MacBook Pro!)