Apple, ARM, and a hybrid OS
Warning: crazy wild speculation ahead.
There have been rumours recently about Apple using ARM chips in laptops. This would be a baffling move.
Intel has been king of the hill when it comes to x86 performance, and isn't likely to lose that crown any time soon. Power consumption of x86 chips has been coming down, performance has been going up, and x86 has the all-important compatibility with Windows apps that, like it or not, is important to a lot of people.
Apple certainly has some good reasons to consider making an ARM-based laptop. They own the chip design, for one, so the chips are cheaper. And Apple's series of ARM chips (the A5, A6, and A7) have been very well suited to mobile applications, offering great performance and low power consumption. But they're not x86 compatible.
There's only one scenario I can imagine where Apple would be willing to ship a new laptop with performance significantly below that of existing laptops. A new category of machine.
I'm going to make a weird sort of prediction here. I think Apple might be experimenting with a hybrid laptop.
There's a fundamental problem with the transition to mobile. Touchscreens are good for some things, and keyboards for others. You really need both. But it's very difficult to build a single application that's great in both worlds. Microsoft has demonstrated this clearly with the Surface tablet and Windows RT.
Microsoft has tried to make a single OS that works for both touch and keyboard/mouse, and created a sort of frankenstein that nobody really likes.
Apple went the other way, and created two different OS's. OSX and iOS. OSX is great with keyboard/mouse, and doesn't try to handle touch. iOS handles touch beautifully, but isn't very good with a keyboard and doesn't support the mouse at all.
But underneath iOS and OSX is the same OS: Darwin. They're both built on Cocoa, and share a lot of the underlying infrastructure.
What if Apple made a hybrid laptop that could run both AppKit (the Mac UI framework) and UIKit (the iOS framework)?
The OS would actually be the same for the most part. I'm not thinking of a dual-boot scenario, where you have to quit one side to start the other. If Apple devised a new hardware form factor that gave you both the tablet experience and the laptop experience in one device, the OS's presentation could change on the fly. At your desk, you're using what looks like Mac OS, but switch to tablet mode and there's the Springboard.
The Mac and iOS have been moving to a model where your application data lives in a defined location, and iCloud has been syncing that between devices. It's quite feasible that apps like Pages or Numbers, that exist for both iOS and Mac OS, could switch seamlessly from tablet to desktop mode and back.
And if Apple did ship a brand new machine that worked this way, then they could break with x86 compatibility. This would be an iPad Pro, not a new kind of laptop, so it would be okay for it to be slower than a MacBook, and the lack of x86 compatibility wouldn't be so bad.
This is a crazy idea, but I mention it because I think there is some motivation there to solve this problem, and because Apple has the technical underpinnings to make it work.