Earlier today we guessed that Apple would be launching Mountain Lion tomorrow, and it turns out that we were correct. During it's earnings call today, the company announced that OS X 10.8 Mountain Lion will hit the Mac App Store tomorrow, July 25th. Users will be able to purchase the OS X update for $19.99. Be sure to check out our getting ready for Mountain Lion guide, as well as our Mountain Lion Mac compatability list to be sure your computer can run the new OS.