I actually think that having multiple releases solve a lot of manufacturing, logistic and gross margin problems for Apple. If you look at Apple earning report over the years, 4th quarter has always the high water mark in term of revenue. But one big problem for Apple to keep going in that direction has to do with the supply chain and logistics.
Apple cannot force the timing of innovation and manufacturing solution from the suppliers. Last year, they paid dearly for Ipad mini GF2 technology (both in term price and available quantity because of yield problem). This year, they look to have problem with Ipad min 2 retina display. That is because they want to have all these new technology available in 4th quarter.
If Apple roll into a multiple releases a year schedule, they can move technology into their product a lot faster. If a technology is ready in March, release a product that make use of it instead of waiting until Dec. And if a product is not ready for 4Q, let them go to 1Q and avoid paying the penalty of yield problems.
It also smooth out the production and logistic problem as well. It is not easy to manage a manufacturing line with big burst of demand in one quarter and very little demand in the next. They have to layoff workers, and then later bring back another group of workers and start the retraining process. Shipping all the new products in one single quarter stretch the logistic and cost Apple bucket of money to have to charter plane to fly directly from China etc.
And it will help the gross margin as well.. Apple is big enough that it can move the price of the common components by itself. If they can smooth out the demand of the wifi chip, dram, flash drive throughout the year, they won't see the price spike in 4Q every year..