Images have leaked over in China showing a device running on iOS 7 that is said to be an Apple iPhone 6. As there's no video material of the device there's no way of telling if it's a real device and not a dummy but the icons on the screen appear to have been reordered at least.
There are a couple of things about the device that strike us as odd, though. For starters it appears to be entirely made out of plastic, which isn't what Apple usually does for its flagship iPhone (not until the 3GS, anyway). So this might be another c version - as in the iPhone 5c.
Second there's a silver frame around the phone's front that looks similar to what Samsung used in devices like the Galaxy S II and seems unlikely to be featured in an Apple flagship.
At least the flash on the back looks in line with Apple's current two-toned flash on the iPhone 5s. A casing that leaked today shows a single LED flash placeholder, just like dummies we've seen before on a few occasions, including a video.
Finally there's no Apple logo on the back of the device. It could be a sign of a prototype unit, of course, but the smart thing to do is take it all with a big pinch of salt.