But remember, this runs low-end iOS hardware. The second-gen ran an A4 SOC and the third-gen runs a single-core-binned A5. My guess: the new model will be a low-volume prototype for a new, cheaper SOC (or cheaper manufacturing process on an existing one) to be used later in iOS devices, much like the iPad2,4 was a prototype for 32nm HKMG manufacturing later used in much higher volume with the A6 and A6X.
An interesting guess. Apple must have a reason for doing this “new" Apple TV (even if they claim it’s no big deal). The only thing that makes sense would seem to be a test of something. Either it’s a new chip or a new manufacturing process — perhaps without Samsung’s involvement, as Arment also speculates.