Services revenue accounts for 10% of Apple's revenue that includes apps, books, iCloud, Apple Care which would be affected minimally by apps available on the AppleTV, music that would be affected more so and then tv and movies which would be affected the most. Movies and TV are a small portion of those services revenue and the conversion of those products into profit is lower than that of their hardware divisions, I'd argue that's a small portion.
I'd be shocked it the AppleTV isn't considered to be a more impressive and useful product than a Roku or Fire TV after tomorrow. It's supposed to have superior game support, smart home integration, exclusive services you can't find anywhere else and the App Store will almost certainly surpass that of Roku's or Amazon's by the end of the year.
Siri integration, games and smart home integration are ultimately going to be it's main selling points.