Why not?
- Macs aren't even using the desktop line of x86 Intel chips
- ANYTHING written adhering to Apple's coding guidance, using toolkits like Accelerate, etc, should be platform independent.
- I dare say the PPC/Intel crossover disaster had a lot more to do with vendors not wanting to support Mac than anything else. @work we port VERY LOW LEVEL (hardware interfacing) code between PPC and Intel all the time and it's not a big deal. There's a lot more support now due to all the growth, I think you would most certainly see major apps ported right away (even Office, which already will be running on ARM..)
- Plenty of people are already coding for ARM platform on iOS -- browse issues of these developers, and you will never see an issue that pops up because of the architecture. Whether you're on Intel or ARM it is basically transparent
- Windows 8 supports ARM so bootcamp is still viable (you're going to see a shift toward ARM anyway in the next 3-5 years)
- Esp. as process gets better i.e. 10nm it's getting easier to get much higher performance, even at the point we're at now there's no real need for more processing power boost even from 1.7ghz MBA unless you're doing something silly like gaming. Even then, it's very capable. ARM chips will surpass that performance in the not too distant future
- So many "PROS" talk about how they won't be able to do their job with less performance -- face facts, what is so high performance in Apple's lineup right now? (Very) old XEON chips? Laptop grade chips in iMac/MacBook/Mini? If you're a "PRO" and are still on the Mac platform and haven't already woken up and smelled the coffee, you better get on it, and switch