Bingo - I bought one just to keep on the shelf in case I ever have to access one of the old backups.
To the other poster: I'm sure Apple waited a long time to try to force folks to upgrade. If they'd done that early on, there'd be more laggers than there are. And since 10.6 is out of support now, they didn't want the PR issues associated with a high number of folks running an out of date OS and having problems.