Just saying, but the 2015 Macbook(s) don't support Windows 7 in Boot Camp (Apple's dual boot support), making it basically useless. Sure, you could use virtual machine software but it's another sign that Apple doesn't really value x86 compatibility at all anymore.
I don't know if it makes it useless, as Windows 8+ is still supported, as well as Mac OS X but I would agree that it's utility on the OS side is diminished. I think the hardware side is even more of a disappointment, it targets to narrow a user and forces people to have a hub for video/usb/... I don't understand why the couldn't have at least put another USB Type-C on the other side (which would still require an adapter) to provide for connectivity. They're pushing iCloud hard on this kind of device, and while I can see why they might try to do that, it would be best to save that for the iPhone and iPad.
Thala said:
In my opinion, it is time that someone designs a desktop class ARM CPU. ARM itself is not particularly interested however Apple might take the opportunity.
When you say desktop class, are you referring to the marketing term that Apple used with its iPhone 6|A7 presentation?, or are you referring to an actual desktop chip (50-90W TDP)? The answer really depends on that difference.
If you're referring to the verbiage of the first question, then lets see what the A9/X will bring in terms of performance (focusing on single-core). That will help provide an idea of what in the near-term is possible in potentially having enough performance to go into MacBooks. Other than that I don't see that happening from another vendor.
If you're referring to the second question, then no, only AMD will still put out products of that TDP and that will continue to be x86-64, maybe a try at ARM but I'd lean towards no on that.