So in other words, mouse + keyboard + iOS/Android will become the dominant system for everyday office use, such as word processing and writings emails? I can be

So in other words, mouse + keyboard + iOS/Android will become the dominant system for everyday office use, such as word processing and writings emails? I can believe that. As you said, the fundamental difference at that point between mobile and traditional computers is the OS. But if that's the case, then I have to question how relevant the distinction is from a developer's point of view. To cater to mouse + keyboard + iOS/Android users, we don't need to build native iOS apps. We can just as well build regular old web apps and ensure they work well for mouse + keyboard + iOS/Android. That's not very different from what we do today, except for the fact that we'd have to account for yet another set of screen sizes. Therefore, as far as serious/business/professional apps are concerned, I don't foresee a major paradigm shift. More like a pressure to learn some new web dev techniques, such as responsive design. Again, though, I don't claim this would hold true for consumer apps. Many of those will likely be used from an iPhone or an iPad without any external devices.