To be fair AMD caused it by pushing AMD64 instead of us going to IA64.
Either way though it wont be as bad as people think. Apple is still a marginal market share and has very little bearing on the overall PC market. I also wouldn't be surprised if a lot of people get upset since now all their software will be useless.
I am not sure we will see major changes even with MS doing ARM. They are doing it because its smart to do but people hate and resist change, its why AMD64 won so easily over IA64, so it may be interesting but we may not see any real change to the consumer desktop market apart from AMD having more market share.
IA64 had a very large instruction word that depended on huge amounts of software optimization by the compiler that never materialized. It pushed even further into what made CISC CISC. While ARM has become more CISC like they are still a much simpler architecture beneath. One of the things that makes CISC chips so complex is circuitry for legacy modes, including memory access. Do you know how many modes there are to support memory access? I think it was 8+, last I counted. Local 64K Paged jumps, Base, System, Extended, Expanded, Virtual, contiguous 32 Bit, 64 bit. It's insane.
However I think Apple moving to ARM for desktops is just going to kill off their desktop brand. Overall this is a bad decision. While they MIGHT get better performance for recompiled applications, Apples desktop and laptop sales have been going into the sewer. Prices have sky rocketed, while quality has actually gone down. The real effort here is to control margins as Apple gets a bigger revenue slice on new hardware if they control all the chips. Plus it locks out Hackintosh systems.
The only saving grace for Apple was, IMHO, the dual boot mode so users could access windows when they needed to run applications that were commonly available only on Windows. Windows adoption for ARM has been painfully slow and app compatibility slow and unstable.
If you remove this capability to run Windows in CISC efficient mode, then you will remove the ability of Apple users to dynamically switch between environments. Recompiled CISC emulation is never efficient and never guaranteed compatible. For example, I can dynamically issue a flag to set the number of bits the x86 FPU uses for computations. I can use 80 bit, 64bit, 32bit and 16bit. It is an assembly instruction. You
can't do that with ARM. 80bit IEEE internal is an x86 thing. It would have to be emulated, or you risk getting different results back. A lot of MIMD and SIMD instructions would have to be emulated to ensure compatibility. And MIMD and SIMD instructions are used extensively for things like video editors/encoders,decoders/CAD/3D.
We have a few testers here that love their MAC desktops. However they haven't updated their hardware in years. And whenever they log into work, they have to go to Windows boot to do work. I would love to see the dual boot mode statistics. I bet Apple has them.