Apple's satisfaction still leads the mobile industry, not just its sales volume. As mentioned at Daring Fireball, the poor turnout of 4G phones raises questions about whether Apple will make its next phone 4G – if it does, it risks the battery dissatisfaction seemingly endemic to 4G hardware. As shown by infrared photography, Apple's new iPad has increased heat – likely a result of increased power use by the product's new 4G, graphics, and display hardware – I believe directly related to the new iPads greater thickness and weight: all that performance requires more battery.
Adding less than 1mm to an iPad may give a lot more battery volume than adding that little to a phone. We'll have to wait to see what Apple does with batteries over the next six months, and whether Apple manages a technical miracle with the next phone.
Anyone have intel on when Apple will move to a smaller manufacturing process for its in-house chips? From 45nm to 28nm for the A6, as rumored here and here? The smaller process would reduce power consumption for the processor – and the more Apple crams into its system-on-a-chip, the more power savings Apple can expect from the improved manufacturing process. In the original iPad, Jobs said the power-eater was the display ("It's all about the display. Our chips don't use hardly any power."); does this remain true in the age of higher-performance silicon?
The answer to these power questions will govern the design limits within which Apple works on the next phone. If the display is the power-eater and the iPhone's display will not approach the pixel count of the new iPad, the phone may not face as much consumption increase in its next iteration as the iPad did in its last. On the other hand, the phone has a lot less room for a battery ....