The iPad can’t get better at these tasks without becoming either more like an iPhone or more like a Mac. For the iPad to become just as good as the iPhone, it would need to be smaller, equipped with a better camera, and sold with carrier subsidies and mobile data plans. But this would turn it into “just a big iPhone.” So this can’t be iPad’s future.
For the iPad to become just as good as the Mac, it would need to be larger, faster, equipped with expansion ports, and powered by software that supports legacy features like windowed applications and an exposed file system. But this would turn the iPad into a Macbook Pro with a touch screen and a detachable keyboard. This can’t be iPad’s future, either.
This analysis mirrors my own usage patterns—since getting a more powerful MacBook Pro about a year ago (about seven months after getting a more powerful iPhone), the combination of the two have become my go-to devices more often than my iPad. My iPhone 5 is capable enough to be my go-to device for just about everything, and anything else immediately falls on my Mac. It’s not that I don’t enjoy the iPad as a device, but it has become better suited as a secondary device for specific tasks.