It's not uncommon now to see Android smartphones with screens at least 4.5 inches in size. Although iPhone 5 will probably have a 4 inch screen, I still don't think this is a big enough increase from 3.5 inches. They've also kept the width the same - probably so that it can be used with one hand. This is useful but hardly necessary since touch screens demand your complete attention anyway and its difficult to do other things whilst operating a touchscreen phone.
What I think Apple need to do is essentially expand the iPhone product line into three products.
1) iPhone 5. 4 inch screen as rumored.
2) iPhone mini. Keeps the 3.5 inch screen but with the same ratio as iPhone 5. Smaller form factor than iPhone 4S. Use of smaller components will allow more room for a similarly sized battery to the iPhone 4S, in conjunction with the continued use of the same processor as the iPhone 4S but with enhanced power management and optimisations and no 4G. Cost less than an iPhone 5 so to appeal to lower end of the market. This will eliminate the need to continue to sell older generation iPhones alongside iPhone 5.
3) iPhone Pro. 4.5 inch screen. Quad core A6 processor. 12 megapixel camera with xenon flash and larger aperture lens. Bigger battery than standard iPhone to offset higher power consumption.
What I think Apple need to do is essentially expand the iPhone product line into three products.
1) iPhone 5. 4 inch screen as rumored.
2) iPhone mini. Keeps the 3.5 inch screen but with the same ratio as iPhone 5. Smaller form factor than iPhone 4S. Use of smaller components will allow more room for a similarly sized battery to the iPhone 4S, in conjunction with the continued use of the same processor as the iPhone 4S but with enhanced power management and optimisations and no 4G. Cost less than an iPhone 5 so to appeal to lower end of the market. This will eliminate the need to continue to sell older generation iPhones alongside iPhone 5.
3) iPhone Pro. 4.5 inch screen. Quad core A6 processor. 12 megapixel camera with xenon flash and larger aperture lens. Bigger battery than standard iPhone to offset higher power consumption.