Every once in a while, I accidentally find a part of the Internet that has different priorities than I do. For example, I imagine that the folks in /r/thinkpad spend a fair amount of time posting things like this.
The core concept of that thought process, and a lot of people in a variety of places engage in it, is that laptop performance has stopped improving and that it won't be improving any further, because laptop wattages and voltages have done down.
In the real world, a few things are true. The first is that Windows, BSD, and Linux are a lot more efficient than they've been for a while, and most workloads at this point involve viewing web sites, which while not exactly trivial, is also something that can easily be done on relatively old hardware. I have no problems imagining most people would be able to use a relatively well maintained old Core2Duo laptop for their productivity and web site needs. It's one of the reasons small Windows tablets and the least expensive of laptops using Atoms are so popular and so much more reasonable today than they have been in the past.
It'll be interesting to see what the next few generations of laptops are like. There are 28-watt mobile chips that exist, which is a nice compromise between the 5 watts of Core M and the 15 watts of the mainstream U-series chips, and the 35-watt dual core chips in systems such as the ThinkPad T440p and the Latitude E6440.
The intriguing thing about the E6440 and T440p is that they continue to offer what their predecessors did the last time I bought a new computer: they're nearly as powerful as a desktop computer at everything except graphics horsepower, where they're just about competent enough to play a few low end games and where the acceleration they've got may or may not be of any assistance to tasks such as photo and video editing.
The biggest problem is that those systems are usually on the far end of the "portable" spectrum and are priced similarly enough to real "mobile workstation" systems with certified graphics solutions, or to gaming laptops, with GPUs that are going to be better for gaming.
Another trend I think will help reduce power usage and make these low voltage CPUs make sense to more people is Thunderbolt 3. For the most recent iteration of this high speed interconnect technology, Intel is allowing discrete GPUs to be installed in an outboard manner, both with the internal display and with monitors, in a docking fashion. The prototype that Intel showed off this year was a relatively thin device with some cooling and a relatively high end AMD Radeon Mobility chip, which should assist with using a laptop for games, since many types of games can reasonably be played with a dual core CPU, the main limitation being the graphics chip. I suspect this will be uncommon, but somebody could have two different outboard GPUs if they wanted, one that can stay in a bag or backpack that can be used when they're away from home, and one (a beefier one, perhaps with a better GPU and more options such as some storage and more ports) one for home.
Perhaps my biggest question is whether buyers of these systems are using them for anything interesting, or if they just exist for historic reasons. As far as I can tell, the Adobe Creative Cloud runs very well on 15-watt hardware (even easily throttled systems like the Microsoft Surface Pro 3) and the prevalence of solid state storage on most modern premium laptops makes it even better. I think the biggest problem with the class of laptops that still has 35-watt dual core CPUs is that the people buying those systems (for upgradeability) are going to run them with slow disks and are only using them because they feel that their "real work" merits more than the capabilities of a 15-watt system.
What's interesting is that with the ThinkPad T450, we're seeing the use of higher density memory combined with some soldered RAM to allow for 20 gigabytes of system RAM, along with the ability to run one or more M.2 solid state storage device and a 2.5-inch SATA device. The CPU performance is predictable, but the other features make the T450 one of the more compelling UltraBooks for power users, who will want things like a lot of RAM, multiple storage devices, several ports, and so on.
That said, I think that except for Macs (none of which can currently run that much RAM), most people don't need those things.
Computing has become interesting. Local computers are more powerful than ever, and for somebody who has a long upgrade cycle, more than a few years, you can usually move down a price level and still experience a reasonable improvement in performance. I've long wondered what happens when all your applications launch instantly. For how many people is there any room to improve at that point? Even previously heavy tasks such as photo processing are increasingly trivial and either happen nearly instantly, or are quick enough that nobody cares about waiting for them.
I suspect the real market for a machine like that is shrinking, which is part of why it's interesting to see so many of them still existing. Perhaps they're more popular than I thought, or perhaps they're all just about to be discontinued as laptop vendors start building their Broadwell and Skylake systems in force.