Well, of course OS X as it is won't run on an iPad. But it's not that technologically difficult for Apple to make a hybrid OS that would run on both tablet and desktop, like Microsoft did with Windows 8. I do think Apple would converge the operating systems at some point, but maybe not anytime soon. I'm thinking not in the next five years. For now, Apple seems satisfied with keeping the tablet and desktop OS distinct from each other, while adding more features each year so they work together more smoothly. Like you can share iCloud tabs between iOS and desktop Safari, you can use iMessage from Mac and iOS, iWorks documents work on both platforms, etc.