March: iPad
June: iPhone
September: iPod touch
Sticking to that cycle makes a ton of sense. They need to produce the A5 chip for all three devices. Launching each device exactly three months apart is ideal.
Basically.
January to March - Start producing components for new iPad so that there is enough supply to meet the sky high demand for iPad at launch.
March to end of June - Start producing components for new iPhone so that there is enough supply to meet the sky high demand for iPhones at launch.
July to September - Start producting components for new iPod so that there is enough supply to meet the sky high demand for iPods at launch.
September to December - Product each of these devices in larger quantities and restock the supply chains so that Apple meets the demand for the product at Christmas.
So basically, some iOS product is on the news constantly year round being talked about and reviewed on tech forums.
That cycle works very well for them, and is something they follow around the world. I don't see why they would screw it on account of one carrier in one country (Verizon).
If they skip an iPhone for an year, the old iPhone starts to feel ancient very quickly. The iPhone 4 is already starting to feel a bit outdated in the sea of smartphones with dual core cpus and gpus.
I'm due for an upgrade this summer, but I won't be upgrading to an year old device when everyone else is offering brand new dual core cpus/gpus. Screw that. If apple skips out on an iPhone this summer, I'm going android or maybe even Palm or Windows Mobile 7, depending on whoever has the most compelling hardware out this summer.