The first signs of iOS 7 and the iPhone 6 have been popping up in app usage logs, according to The Next Web, who received word from unnamed developers. According to the sources, hardware is currently being tested by Apple showing an iPhone6,1 identifier, similar to the iPhone 5's iPhone5,1 identifier. The device in question runs iOS 7.
The sources provided some developer logs, which show, among other things, an IP address from the Cupertino campus for app requests, indicating that the Apple posse is testing currently available apps for compatibility. Aside from these slivers of information from the usage logs, sources have stated that Apple will complete iOS 7's features in the near future.
Back when developers first began seeing traces of iOS 6, it was unveiled at WWDC in June soon after. If the same pattern holds for iOS 7, we'll likely get a look at it come the conference this summer, nearly exactly half a year from now.
Of course, there's no proof that the supplied usage logs aren't tweaked with fake info. Keep in mind that the information comes from potentially unreliable sources, and that nothing official has been confirmed. The Next Web states that it believes the logs are legitimate because of the IP, but until something more legitimate comes our ways, take it with a grain of salt.