I thought they already said this at the Build conference, no?
They are asking them to develop Windows 8, Win Phone 8 and Xbox One all at the same time. Which is why they are asking developers not just to publish on X1, but all 3 platforms.
They are trying to unite the platforms. It's actually a rather cool idea if it can work. Heck, they made Windows 8 run on ARM, so I bet they can make it easy for developers.







