OSX 9 Mavericks is ready for the public, not just developers. I’ve upgraded a MacBook Pro Late 2008, the installer only asked if I wanted to continue but after that I didn’t get any other question. Once the installation was complete about half an hour later, I could just carry on working where I left off. So far, my laptop actually feels faster, and I am hoping that the battery would last longer on a charge. That’s the only thing I need to witness now before I declare this a great great OSX upgrade.