Rafe Colburn tries to pass off a real danger as "move along, nothing to see here" thing:

Basically there are two kinds of software out there. Software that's too big to die, and software that isn't. If the software is too big to die, then it doesn't matter whether it's open source or not. If MySQL AB were to shut its doors tomorrow, the MySQL database would be just fine. Companies like Google and Yahoo rely on it, it's provided by hundreds of hosting providers, and it's mature. It's no more likely to suddenly go unmaintained than Microsoft SQL Server or Oracle.

That's true to an extent - even users of IDMS still have a home, for instance. Having a home doesn't mean that support will be cheap though. Quite the contrary - moribund legacy-ware is usually a very expensive proposition. The danger isn't that support would dry up - rather, it's that it would suddenly get very, very expensive, and possibly hard to get.