Before we get hysterical here ...

MySQL will continue to be free/libre. MySQL's API for attaching backup tools will remain open. Before acquisition by Sun, MySQL had planned to develop a completely new and freestanding "Enterprise backup tool" using this API, and had not decided how it should be licensed. Ergo, it must be the case that Sun is taking MySQL proprietary. Not.

You guys really don't understand where Sun's going. I would think it's far more likely that Sun will decide to make this tool free/libre, and then offer paid for training or implementation services.