Back in 2010, a few months after the iPad's release, Steve Jobs predicted that tablets would eventually overtake PCs. Now, according to updated figures from Gartner, after five years of rather crazy tablet growth and slowly declining PC sales, 2015 will be the year that Jobs' post-PC dream is finally realized. In 2015, Gartner predicts a total of 320 million tablet sales, versus just 316 million PC sales (desktops and laptops) -- and that's an optimistic figure, too, that presumes businesses will continue to upgrade to Windows 7, and that Windows 9 (probably due in 2015) will drive increased PC sales.