All channels that have been released up to this time have been released when both the Apple TV 2 and 3 have been getting iOS updates. The more recent Apple TV iOS updates were only for the Apple TV 3. Because of this, it is not possible to discern whether or not the Apple TV 2 will receive any additional apps. However, it is very likely that there will be firmware limitations for HBO Now that will exclude the Apple TV 2 as it only runs up to iOS 7.1.2. As for your question, there are a few local specific apps that are only available for the Apple TV 3.