In 2007, the company known as Apple Computers became simply "Apple". This was an important sign of things to come, as Apple has continued to grow by innovating in the world of devices - rather than sticking to 'computers' in the traditional sense.
Apple's success in the iPod portable music market allowed it to innovate in the smart phone market. The iPhone made "mobile internet" a reality. Since then, Apple has invented an entirely new market - that of the portable tablet, through the iPad. Rumor is now rife that Apple is planning to create its own TVs - beyond just the existing set-top box offering that is the Apple TV.
While the iPad may just be a "bigger iPhone," jumping to the TV screen seems a much bigger leap. The iPhone and iPad and interactive experiences. Innovations such as multi-touch add a lot to the experience. In contrast, TV is generally a passive experience. Any innovation in the experience is likely only on the few minutes during which you switch channels. However, the original iPod was itself a passive experience - most of the time, you are simply listening to music. The innovation with the iPad was the wheel, for switching between songs, and the delivery mechanism - the iTunes store. In the case of an Apple TV, as well as innovating on how we might switch channels, there is no doubt that, for Apple, an iTVStore would make a great addition to Apple's existing iBookStore, iTunesStore and AppStore.