ARM Macs better come soon because we need cheaper MacBook Airs that are around $500-$700. Broadwell-U CPUs from Intel are around $250-$400, and that's not going to cut it for a $500 Macbook Air price point. The CPUs need to be around $50-$100 to hit that price. We could also use a $300 Mac Mini as a small office server, in which an ARM cpu would work well.
intel should be scared. Apple is already at speed parity for the low-end CPUs, and by the time the A10x rolls around, they'll be as fast as Intel's top CPUs.
Apple's ARM A8x cpus are as in the same ballpark speeds as any 10-watt Broadwell CPU. And, given a higher power budget, they could easily go 2-3x faster, putting them in ludicrous speeds. A fully configured 10-core version for a Mac Mini server could even be 10x faster, and wouldn't cost any more than the A8x if they took out the GPU.
Just ship ARM, and have all the vendors just recompile their OS X apps for ARM. No one needs Windows compatibility (I don't know any Mac owner that uses Windows) and the .25% of Mac users that do can go buy an Intel Mac.
ARM doesn't have x86-64 instruction set supporting CPUs.
Only Intel and AMD have those.
1) So if Apple brings out a MBA with an ARM CPU, it will be just an overpriced competitor to Google's Chromebook.
Not a good idea.
2) Count in that AMD went from a real Intel contenderwith their Athlon series CPUs to a "niche" player after Intel introduced their i-series CPUs, so ²even if Apple switches to AMD, they will be running behind in the CPU market. Not a good idea.
3) Apple is itself a niche-player with their Intel/OSX Macs compared to the vast majority of Intel/Windows computers in the world. Corporate world and the majority of home systems are Wintels, that's something you can't deny.
4) Yet, just because Apple went Intel a few years ago, a lot more of the Wintel based software gets overported to Intel/OSX than in the past when Apple was still running on Motorola's PPC CPUs.
5) And not only the Wintel software, but also a lot of the Lintel sofware (Intel/Linux) becomes easier to overport, due to the the x86-64 instruction set and the FreeBSD origin of OSX.
6) For some software there isn't even today a Mac-version or Mac-software that can do the same that is an industry standard, so being Windows compliant is a benefit.
7) Other software is an industry standard (MS Office comes to mind), but would Microsoft create an ARM-based specially for Apple if Apple minimizes its market-share by switching to ARM? Now they do that because it's profitable, iOS is big and Intel/OSX is profitable, but an ARM switch would decimate their Mac customer market, which would reduce also their iOS market (they are connected) and that could have the affect that it won't be really profitable for MS to create an ARM version for OSX and iOS, which would further push Apple into the niche market.
The industry isn't going to make iWork the standard at all.
If Apple wants to keep it's Mac line (iMac, MBA and MBP) and with "keep", I mean "having a computer line at all" instead of becoming again just as small at the time of their PPC days, they will not switch to ARM or even to AMD.