Nearly all of the comments in this thread are extremely negative - ranging from hand-wavy about how valuable mobile is to expressing excitement that "[dumb] people will [again] be leaving the Internet." What an incredibly pessimistic and self-centric way of viewing the world.
The incredible thing about a supercomputer that fits in your hand isn't that we're putting them in the hand of hackers who went to MIT 40 years ago. It's not exciting for someone who was going to be sitting behind a Linux terminal anyway. This pretty much changes nothing for them.
But it changes everything for the kid in sub-Saharan Africa who has never had access to a computer. It changes everything for my friend's family in Iran - none of them ever had a computer, and now all of them have a smartphone.
It even changes everything for my father-in-law - a hay farmer who had little interest in using a computer, but inexplicably loves his iPad. He takes it out to the farm and performs what I would consider the most trivial of computing tasks, but it's something he never did before, even when PCs were cheap and ubiquitous and I spent hour after hour teaching him how to scroll and double-click.
Of course, hackers are right: That smartphone is not be as good at editing photos as your 15-inch Macbook Pro. And it's a horror to write code from. But, to borrow an analogy from Peter Thiel, the difference between editing photos on your phone and editing them on a computer may be a move from 1 to n for hackers. Hackers, who have been at n for years, are rational in not caring. For this Iranian family, and for my father-in-law, however, this is a move from 0 to 1. And that's a big deal.
Are the operating systems more closed than hackers would like them to be? Yes. But my friend's family in Iran has neither the interest nor the ability to hack on the kernel of some mobile operating system, so they don't really care. Is it harder for them to type on a phone than it is on a keyboard? Of course, but now they're typing something. It works, and they're using it, and that's a big, big deal.
This isn't necessarily a revolution of what it's possible to do with computers, but a revolution of who can do things with computers. We'll soon be reaching economies of scale we could never imagine. Access, where there previously was none.
That you can call an Uber because it's in your pocket and happens to include GPS, in my mind, is just a side-benefit.