In our "Let's talk iPhone" event rumor roundup, we noted Apple could announce a new Apple TV on stage. Earlier this year, a number of separate reports have suggested Apple was working on a new Apple TV with A5 CPU (the same of iPad 2 and iPhone 4S) to enhance the device's processing capabilities and allow for full 1080p playback. The current Apple TV model packs and A4 processor (iPad, iPhone 4) and plays back video up to 720p, but as we know the October 4th event didn't see any Apple TV updates among iPod, iOS 5, iCloud and iPhone 4S announcements. A rumor from July even suggested Apple was working on a new video format called HD+ to launch this fall in the iTunes Store alongside a new Apple TV model.
According to a code string found in iOS 5 by 9to5mac, a new AppleTV3,1 is in the works, and it should be an updated version with upgraded internals such as the aforementioned A5 processor. The existing Apple TV model is referenced as AppleTV2,1 -- Apple typically uses this kind of references to prepare iOS for upcoming devices. References in the iOS filesystem are never 100% accurate, but new devices found in the past through code strings have turned out to be real most of the time.
With Apple pushing towards 1080p video content with the new iPhone 4S camera and AirPlay Mirroring made possible by the A5 CPU, it wouldn't be a surprise to see a refreshed Apple TV with faster CPU and more powerful video processing capabilities. As a side note, Apple recently started selling the current-gen Apple TV in more European countries.