It isn't a generic spec bump if you look at the scores... if Assistant is all people are saying it is cracked up to be that would be enough of a wow to bring people in... plus everything else in ios5, plus the extremely popular and sexy shape of the current phone...
the basic form factor didn't change through the first 4 models--went from metal to plastic, but correct me if i'm wrong--the major changes in earlier models were always "spec bumps" or the addition of some bit of hardware--3g, for example. It seems to me that dual core plus a new graphics chip fall in line with this kind of change. It might disappoint people who come to macrumors and speculate for months before a release, but for the lay person it is plenty... with the possible exception of those who have been sold on the necessity of 4g, which I just don't buy personally.
You have it mixed up. The 'lay person' doesn't care about specs. How would he know the difference between the A4 and A5 chip? Why would he care if the graphics were improved from the PowerVR SGX 535 to the SGX 543MP2? Does he even know what a core or RAM is?
What the average Joe does care about is what it looks like. Joe doesn't want to plunk down $200 for something that looks and (seemingly) functions identically to the phone he has in his pocket, the one he paid $200 for one year ago.
The same theory could be applied to teenagers- if Little Joe's iPhone doesn't out out of date to his mates, then he won't ask his parents to buy the new model for him- after all, he won't be perceived as any more cool than he is now.
The people who go to MacRumors etc on the other hand do know about the improvements the 543MP2 brings to the table over the 535. They do know how RAM makes Safari less prone to reloading pages while multitasking etc. They do know the advantages of a dual core processor over a single core.
Unfortunately, everyone has noticed those new Android/WP7 phones coming out with their ginormous screens. The people who go to MacRumors will ask Apple for the new iPhone to have a larger screen, but they'll stick with Apple no matter what because their music etc are all integrated into Apple's ecosystem. However, maybe Little Joe will see those big bright Super AMOLED Plus displays and think, hm, maybe this will let me share YouTube videos easier with my friends and boost my 'cool rating'.
So. The people who read MacRumors and have everything integrated into the Apple ecosystem (especially apps) will most likely stick to Apple for the near future, larger screen or not. They'll see the advantages of the A5 chip and happily sell their old phone for the new model, new housing or not.
The layperson on the other hand, who can't do much more than check stocks and make calls to business associates (for the average Joe) or play Need for Speed and text message (for Little Joe), might find that the competitor's product does what they want, and since it looks different to what they already have, they'll happily pay for it.
