Apple the "artistes"
Apple has been very clear about not doing something unless it "revolutionizes an industry".
You can't depend on someone with such an attitude to provide stability, predictability, or the "boring" infrastructure that comes with just doing a great job producing reliable computers. They need to be walking around on stage showing people the wonder that they are. And the crowd goes wild when they see the device now comes in colors.
"You mean you can pinch AND flick? OMG!"
More sober vendors (SGI, HP, Sun) go around to major customers and have presentations where they lay out their technology roadmap for the coming years, so their customers can plan also.
This is 180 degrees opposite Apple, which always has to astonish and "surprise" their customers, equating surprise with revolutionize.
In a sense Apple is living in the past, always trying to recapture the moment of the introduction of the microcomputer in the 1970's. That set the template for their self-image, even though in part it came from accidents of history and timing.
Apple should have a different business unit committed to following-up and maintaining prior "revolutions" instead of dropping them when the hype moves on, while "artiste" Apple can forge ahead dazzling the world (until the inevitable day they don't ... but can then fall back on the rock-solid unit).