According to Patently Apple, Apple has been awarded a patent that it filed over five years ago related to sorting episodic TV content on the Apple TV. Steve Jobs himself is among the people credited with the patent, which on the surface merely appears to describe the sorting features already present in the Apple TV's interface.
Patently Apple dug a bit deeper, though, and found an interesting tidbit referring to menus that "correspond to television shows that have either been recorded from a broadcast or purchased from a content provider." This seems to suggest that at one point there were plans to include DVR-like functionality in the Apple TV; it's unclear if those plan