I remember when the Apple app store first launched. No one knew or understood what a game changer it would be - I guess you could argue that Apple did! When you think about it, Apple redefined the word 'app' to be almost mobile exclusive in modern vocabulary. I'm not sure why I didn't take up Objective-C back then, I was far more interested in things like Ruby, Rails, and building web apps. I did slowly come to learn were things like jQuery, Backbone, Meteor.js, React, etc.
Think about it logically; smartphones are small, compact, and easy to carry. They come in at a lower price point than laptops and desktops. On top of all those positives, they also come with always-on connectivity. They are the perfect storm that will take over the world. There are countries now that don't have high amounts of laptops, desktops, and last mile connectivity. They don't need it; you can just hop on a smartphone or tablet and get everything you need - why buy a computer?
You don't have to believe me, just look at the top camera on Flickr, the iPhone. While it may someday get supplanted as the top picture taking device, it will only be rivaled by another Android smartphone like the Galaxy. People aren't rushing out to buy separate picture taking devices unless they want super high-quality images. Computers, both laptops, and desktops, will go the same way.