The latest iPhone 6 leaks reportedly come from within Foxconn, and were posted on Weibo (a Chinese social networking website). They depict a device that looks larger than the current iPhone 5s, but also slimmer. Interestingly, the camera lens appears to protrude slightly, similar to how the current iPod touch design.
The glass backing has given way to more aluminum, and there appear to be more curves, which will hopefully make the device easier to hold than the current design.
As usual, take these images with a grain of salt; but with a device that has to be produced in such high quantity as the iPhone, leaks like this will happen. This very well may be the iPhone 6.