Sun might be getting a lot of bad PR with their move to close source parts of MySQL (though that may not happen), so it makes sense that in the same week an announcement that would drum up good feelings for them is released. It appears that Sun is preparing to fully open-source Java, allowing the community to more or less do as they please. Sun is attempting to encourage further Java development, primarily on the Linux platform, and is finishing up a process that began over a year and a half ago.
They have a lot of incentive to do so, since with a much larger deployed base of Java software comes an increased chance to offer paid services to Java-using customers. Still, the move is probably a good one for Sun in the eyes of the public.