I still have to disagree there, technology advances pretty fast, but 5 years is just too fast. Apple alone will ensure that, there are way too many people that will buy the newest MacBook and iPhone every year until Apple does away with Macs entirely, and I very highly doubt that’ll happen in 5 years. Also, screen size is an extremely important factor - people want a pocket computer (thus, smart phone), and a computer with a larger screen (laptop/tablet).
The kind of devices people regularly carry with them from day to day hasn’t changed much in the past 10 years - laptop and a phone. The iPhone has been around for 10 years now, and its maybe even more popular now than it was originally. As laptops become thinner and lighter, I don’t think people will feel less like carrying them around.
Looking at the university I’m at, every single person has a laptop, and I don’t think anybody is against having one. There are tons of people without smartphones, but everybody has a laptop. Does everybody need one? Not at all, there are plenty of computers available on campus for students to use, and there are many majors and degree program that don’t require a computer for even a single course. One could get by with just a smartphone if they wanted to. Most students have a laundry list of uses for their laptop outside of school too.
There are also lots of laptop/computer companies that don’t want to go out of business, and I’m sure they will do a good job selling devices to the general public.