The upshot of last week's database news is: You have to make prudent choices when selecting the software you use. No one knows what MySQL, Sybase, Informix, Greenplum, Kickfire, or EnterpriseDB, to name a few, are going to do next week. If you have bet your business on selling a proprietary software application that links against MySQL, you may be in trouble soon. Just like MySQL has been more or less in at least serious threat of trouble for some years now by selling a proprietary version of their software that links against someone else's proprietary version of their software (InnoDB). Or, to leave the database realm for one sentence, by building their development process on a proprietary version-control system.
The question isn't so much whether Oracle will kill MySQL or MySQL will kill itself. Database deployments are very slow to go away, and MySQL's adoption is massive. The question is what will happen to the investment you have made when you chose MySQL. Switching to a different SQL DBMS is extremely painful. Drizzle may now have a BSD-licensed client library, but it isn't going to be a replacement for MySQL, unless you targeted your application for MySQL 3.23. (And Drizzle development, for what it's worth, is hosted on a proprietary hosting platform.) The other forks of MySQL aren't going to help you because they can't sell you license and they are not even allowed to provide you with an updated MySQL documentation.
Of course I will argue that PostgreSQL is somehow positioned more appropriately here, with the BSD license and the way the community works. But this episode shows that open-source software isn't just about free downloads or a fun community experience; it is about protecting your investments, your IT strategy, and ultimately your business.