A lot of complaining by third gen iPad owners about the timing of the fourth gen iPad. So I'm curious… If people could choose the average length of Apple's upgrade cycle for all products (Macs, iPhones, iPads, iPods, etc), what would it be? When answering, forget that some options, like the daily updates, are technically unfeasible! Imagine that for every option, the overall rate of change is the same as you would currently expect, so after 2 years, all the products look the same.