This is something I've been considering for quite a while, so hang on while I do a deep dive into why I believe that OS X will be Apple's last X86 operating system.
For those who don't know me, I am a recent convert to OS X. XP was the end of the line for me, and i had no desire to use Vista, or even Windows 7. I came over to OS X because for what I do (computational protein redesign, protein crystallography, and other protein stuff), it was easier to have the BSD underpinnings. However, I've been a computer geek since my father showed me the Compaq "Luggable" when I was 5.
Apple moved OS X from the IBM PowerPC to the Intel x86 architecture in 2005 because it was becoming quite evident that IBM was not willing to invest resources into chip development, especially since the G5 were so power hungry for their performance. The whole architecture behind the G5 was more geared to big iron where power savings were not nearly as important as in a laptop. Its not really surprising as IBM thinks BIG IRON, not small devices.
Moving to x86 gave Apple access to a much richer hardware environment where the pace of development was much faster, especially since there was competition for Intel with AMD. Economies of scale won out, since all components are essentially common.
But now, we are in a different shift, towards even more mobile devices. Look at the iPhone 4, or my EVO 4G Android phone. These devices have more computing power than I ever imagined I could have in my pocket. And I bought many PDAs, Sharp Zaurus, Dell Axim, many Palm Pilots. But notice, all the modern smartphones run on ARM processors.
ARM vs Intel is RISC vs CISC
The reason we never see x86 family processors in mobile devices is simple, they are just not power efficient. CISC, or complex instruction set computing makes it easier for assembly programmers to write efficient code, but the problem is that the processor is saddled with lots of potentially obsolete instructions that have to be integrated onto the die. This all wastes space and power. This is MUCH better explained by Security Guru and overall genius Steve Gibson of GRC in episode 252 of Security Now (
http://www.grc.com/securitynow.htm) .
RISC is inherently less power hungry, and therefore more apt to being in a mobile device. Thats why your iPad can go for 10 hours. Apple knows this, they purchased PA Semiconductor for the engineers.
The iPad is the first, cautious step.
I think I can see where Apple is going with this, the name change from iPhone OS to iOS makes it clear. Apple wants desktops to move to ARM based iOS, with an Aqua layer. This makes so much sense because iOS has built in touch support, it was made to be power efficient and most importantly, it has a HUGE app development pool.
Now you really think I'm crazy
The change wouldn't need to be revolutionary, but more evolutionary like the move to x86. Current OS X developers would have to recompile apps and maybe rethink some things but imagine this scenario.
You have an iPad V4, it has all your data either on-board or synced to the cloud. You come home, slip it into a wireless dock, and you have a keyboard, mouse, and bigger screen. The interface changes to something more like the OS X Aqua, and you go to work. You want to leave, so you grab you iPad V4, and the on screen interface is like the iOS4 interface, (but with better multitasking). The app you were using (lets say Photoshop), switches to a more restrained but still capable touch only interface, and you still have all your data there.
Desktops will be the same as they are now, just smaller, more like the iMacs. Those who want power will get it in the form of more cores and higher parallelism. If you do lots of video editing, you will still do it on a Mac, but the underlying architecture will be different. I guess one would be ABLE to do the video editing on my hypothetical iPad V4, but you wouldn't want to the same way you don't want to do video editing on a Mac Mini but you could!.
My evidence for this is slim, but it does seem like the future trajectory Apple is taking. Notice that iWork has not been update for a while, and the Snow Leopard 'update' was more of a service pack. Also, note that there where NO design awards for OS X at this years WWDC.
Microsoft is clueless, Google doesn't have direction.
Why in the world would you want to shoehorn a desktop system into a touch appliance using a CISC based processor? I'll just leave it at that.
Google's Android has legs, so what is this Google Chrome OS thing? Honestly, I'm not sure whats going on there, but honestly, I think Chrome OS is a stop-gap for 'real people', while Android is the future. CISC is not going anywhere soon, so that might be why Google is making Chrome for the x86 architecture. If I were Google, I would tell Intel to invest heavily into ARM development.
I've been writing this for a while, so when I heard Andy Ihnatko and Alex Lindsay discussing this on yesterday's MacBreak Weekly, I realized I had to post it. Andy, I must agree with you, Apple will never Open Source OS X. Alex, I'd love to see more custom OS X hardware, but I don't see it happening either.
If you got to the bottom of this thesis, I congratulate you. I just wanted to put my thoughts down on the record. Please comment, i'd love to hear some feedback!