The new APIs in OS X for apps wanting to use the App Store seem to borrow a lot of ideas from iOS. An idea came to me yesterday: is Apple trying to blend the two OSs? If a user tries to use the desktop version of the app or connects an iPad to a monitor, the desktop version of the application is displayed allowing for "real work" to be done with a touch interface or even physical mouse/keyboard. Otherwise, on the go, either the simpler iPad or iPhone version of the app would be rendered, depending on the device.
It's a pretty simple idea, and I feel like I can't be the only one to think of it. But, I can see it working out much better than the "two-in-one" approach Windows 8 is taking.