Why are some Apple products missing from the Buyer's Guide?
Advice in the Buyer's Guide about the timing of purchases is based on the history of intervals between previous releases or upgrades. First-generation Apple products do not have such a history so we cannot make purchase timing recommendations on that basis. Once products start having regular updates we can add them to the Buyer's Guide.
The second generation Apple TV, released in September 2010, is a different type of product than the original 2007 Apple TV, so the time interval between their releases is not a suitable basis for predicting future updates.