When Oracle agreed to acquire Sun there was some speculation that Oracle might try to kill MySQL. First this wouldn’t be a very prudent effort on Oracle’s part and second it’s not even possible. I think Monty has the best explanation from his comment on his blog:
The simple fact is one can’t own an open source project. One can control it by controlling the people which are leading and developing it. When a company doesn’t take good care of their employees and those employees start to leave the company and work on the project elsewhere, that company has lost control of the project.
The whole comment is worth reading. Monty does a good job of putting the Sun purchase into perspective with regards to MySQL and the developer community.