After sharing some retail stats Craig Federighi took the stage to demo OS X Mavericks in all its glory. Federighi demoed some of Mavericks top features like improved notifications, a dedicated Maps app, Finder tabs, tagging and a ton of other noteworthy features.
After he finished giving the demo he announced that the days of paid software updates were over and that OS X Mavericks and all future Mac software updates would be free! Even if you are running earlier versions of OS X all the way back to Snow Leopard, getting to Mavericks will be free and a 1-step installation.
As for the availability of Mavericks it will be available to download today from the Mac App Store. So what are you waiting for? Get downloading!