Quote Originally Posted by vexorian View Post
It is not possible to retroactively change the license of stuff that was already released. So if Oracle do that, there's nothing stopping you from taking the last GPL-ed release and keep on working on it with the GPL.
That's true that you could take the last GPLed release and work with it. But if Oracle changed their license to a proprietary license (which the owner is allowed to do), anything developed from that point on would be closed, and anything forked from an earlier release wouldn't be compatible with future releases.