The current fragmentation of the "smart TV" market is a mess: it's something that a unified environment could easily tear through.

But making the deals with content providers to create that environment is going to be astonishingly difficult. These are companies responsible for messes like http://theoatmeal.com/comics/game_of_thrones , along with the recent removals of films from Netflix by Starz. They love their monopoly on content and would likely be terrified to death by the concept of giving up control to Apple.