What risk? They have demonstrated time and time again that they are not adverse to making the developers jump through a new hoop. They went from low res to high res and that required work on developers part.
Yes but that is different, and I'll explain why in a moment.
I've read bits that have said that if Apple used a certain ratio, that the developers really wouldn't have to do anything at all.
Here's why I don't think that would be smart. Let's take an analogous situation. Think back to 4:3 TVs. When widescreen DVDs were released, you had one of two things happening on your TV screen. Either the DVD player would distort the image by squishing it into the screen or the DVD player would have to display the image with two horizontal black bars above and below the image. Similarly, when you try to display a 4:3 image on a 16:9 or 16:10 screen, either you need to squash the image, or you need to display two vertical black bars on the left and right of the image. The only other possibility in either of these circumstances is to cut up, or blow up, the image to fit the screen. Neither of these scenarios yields an optimal and elegant result. They are all terrible and ugly. The moral is: You don't want to force the native resolution of one screen onto another screen with a different native resolution that isn't optimally suited for the first screen's resolution. That strikes me as a non-starter and I don't think Apple would ever allow such a thing. If you can point to precedent showing otherwise, I'll happily retract my claim.
So where does that leave us? Well, that would mean each app would have to be designed, in its layout, for each display. That introduces a lot of fragmentation into the iOS environment. Tweaking the layout is very different from simply quadrupling the resolution of the images yet keeping the same layout. That is precisely why the work done to go from low-res to high res was small and pale in comparison to having to design software for 3.5" iPhones and design software for all other sizes at the same time. The same reasoning applies to iPad and the rumored 7" mini iPad.
Do you expect the size of this device to NEVER change? Not even 5, 10, 15 years out? Even the most die-hard fan will get tired of buying the same product over and over. Again, small speed bumps just won't be enough. There's got to be something more dramatic, and it can't just be software either.
Let's not engage in hyperbole shall we? First off, you can keep the same screen size and introduce plenty of other hardware and software enhancements to attract customers, so claiming only speed bumps are what lies ahead is a gross distortion. Now, you raise a good question, can we expect the same size Apple phones for the next 5, 10, 15 years? I don't know, and I'll say probably not. But this is pure conjecture, and I think Apple will only make the transition when it is clear to them they can make a better phone in a new size. That day may be this Fall, when they release the new iPhone, but so far as I can tell, right now, there isn't any advantage to these bigger screens as far as making a better phone is concerned. The downsides outweigh the pros. When the scale turns, things may be different.
I think Apple will avoid fragmentation as much as possible, so the question is, would they rather have only a 4.x" iPhone, or only a 3.5" iPhone? A few people probably would rather the 4.x", but I'm willing to bet a sizable portion of the public is still happy with a 3.5" iPhone, and would be happier still with an even smaller, lighter, and thinner phone. So long as sales still far outpace production of the phones, I think we aren't likely to see a change in the size of the screen.
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Making smaller parts such as the dock connector and smaller volume buttons and smaller home button will give the illusion of a 4.5" screen versus the current size of 3.5"!



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Exactly! I think they will keep trying to trim the overall size of the phone, without changing the screen size. There is a lot of room that can be trimmed away from the top and bottom bezel surrounding the screen. There have already been rumors of a smaller home button, so I expect the phone to shrink vertically.