According to AppleInsider, a Chinese publication has obtained components of the forthcoming iPhone 5 and has done detailed measurements. These reveal that the new iPhone will be 18% thinner and that the screen will be 30% larger. These dimensions are in line with earlier rumors. The post on AppleInsider also notes the new smaller dock connector and the relocation of the headphone jack to the base of the device.
As we've mentioned in the past, the larger screen will be achieved by making the device taller. A report on 9To5Mac says that they've discovered that iOS 6 has been engineered to be scalable to the taller display which has a resolution of 640 x 1136.