For those who say we won't see a 128GB model because of iCloud, they said the same thing when ....
Just to clarify what I said specifically, I'm speculating on where iCloud (and LTE) might be by the time a 128gb iPhone is feasible. I agree -- where they are now, I don't see any sensible way in which iCloud does away with the need for on-device space. If anything, the need has become more pressing since now there is not only the stupid 20MB limit on cell downloads but also the capped data plans new users are on.
I suspect that we'll get to 128GB, but it might take a while.
jaytv111 posted the number of days between capacity boosts:
221 days 8GB -> 16GB
500 days 16GB -> 32GB
847 days 32GB -> 64GB
You could look at this as an average (as that user did), but you could also look at it as a trend, which appears to be
slowing. If the apparent trend were to continue, it could be something like 1100-1200 days (more than 3 years) to the next bump.
On the other hand, if hardware and data network (traditional, more than cell) allow it, we could see that very soon, the iPhone hardware allows for more porting of games from the PS2/XBox era, that are multi-GB in size (as opposed to most iOS games right now, which are <1GB). If we see DVD or even BD-based games make the jump to iOS, that would be another major expansion of how much room an iOS device needs.