Lost independence...
It's unfortunate, I think, that IBM has been unable to meet the roadmap. It is highly unfortunate that they were unable to develop a low power, adequately performing G5 for mobile computing.
The biggest issue is the loss of distinction between Wintel/x86/AMD, etc users and PowerPC users. I know that it is somewhat artificial, given that upon moving to a platform independent OS Mac has had the ability to run on x86 architecture for a long time.. however, this just makes us all together in one pool... x86 users.. running different OSs.
I just think that running on a different chip makes a huge difference.. at least, to me.. philosophically. Maybe it's just me, but now I feel like I'm walking in Microsoft's shadow... It makes me feel like I'm using cheap, shoddy equipment. I just can't shake the feeling that the same chip that is running in some POS DELL is RUNNING IN MY BELOVED MAC. And for those of you who are pointing out all the shared components such as hard drives, graphic cards, etc. Foo to you. The chip is the soul of a computer.