If you read the Steve Jobs book, you'll discover that early on in Apple days, a significant (to put it lightly) amount of stock was left in warehouses and never sold. He didn't make the mistake again. They have a very good supply chain which would rather see demand out-strip supply. Regardless, I don't think many people expected this launch to be so backlogged. Usually it's just iOS...
IBM had the same issue. Mountains of PS/2's (computers) languishing in warehouses. Dell was the one that had it right from the start. Build on demand. The tractor trailers are backed up to the loading dock but the components for the computers inside those trucks belong to the manufacturer until Dell goes in and offloads them. Technically, Dell has no inventory of system or parts. Very efficient.