9to5mac has posted a leaked photo showing the upcoming iPhone 5. In the photo you can see a comparison between the black and white versions of the next generation iPhone 5. As you can see in the photo metal is present in the device's back cover. Moreover a smaller dock connector is present and the earphone jack has been moved to the bottom corner of the device.
According to rumors the new iPhone will have a 3.999 inch display with 640x1136 resolution and 1GB of RAM.
Apple's Worldwide Developers Conference (WDC) is taking place on June 11th in San Francisco. Most probably iPhone 5 will be presented there as well.