As a circuit designer, I find it really surprising that Apple has rolled their own processor for the iPad. We finally confirm why Apple bought PA Semi. But it also says a lot about Apple and the processor industry:<p>* Apple predicts that sales will be high enough to justify building an iPad-specific processor. I assume nobody outside of Apple will get to use the A4 or derivative chips.<p>* Apple feels that there was no external vendor that could cost-effectively get the exact power-performance trade-off they wanted for the suite of applications that they want to optimize.<p>* Tempering the previous point, this may be a net loss in the case of the iPad alone in terms of pure costs versus going with an external vendor, BUT they now have much better negotiating power for all their other processor purchases from Intel, Samsung, ARM, etc. They can always threaten to roll their own. So even if they lose some money on the A4, they may be in a better position overall<p>* EDIT: Let me also add that despite what some people are claiming this is likely NOT an ARM, but based on PA Semi's power-efficient flavor of the Power architecture. I believe the Power architecture is in the same family as the Motorola PowerPCs that Apple formerly used and dumped for Intel because of the PowerPC's lower power-efficiency.