The new Apple TV media player has except on a single-core A5 chip has 512MB of ram and also an additional wi-fi antenna to be added. This shows a teardown of the third-generation Apple TV on the Xbmc forum.
By doubling the memory would, according to members in the forum, the Xbmc Media Center software smoother to rotate. This requires the new player still gejailbreakt. The flash storage from Toshiba, and the size thereof is with 8GB unchanged.
The teardown on Xbmc also shows a bare A5 chip. This has as a model number, APL2498, and according to the specifications on the Apple site that has a single-core variant. The current A5 chip in the iPhone 4S and the A5X processor in the new iPad are equipped with two processor cores. It is not known at what clock speed the A5 chip in the Apple TV runs.
Also notice the Apple TV parser on that it seems Apple has an extra antenna added for wi-fi. It is not known which Apple used exactly in the new Apple TV.