There's a lot of talk here about what "I" think should happen, what Apple needs to do to compete etc. But no one seems to have considered how Apple would view this. Apple doesn't design based on the other boys. They don't pick their products by what the other boys are doing. Etc.
From Apple's POV what would be the need filled by this TV set. And how could they "do it better". Those are the questions they ask not "what's everyone else doing" or even "what do the geeks on the blogs think we should do and how do they think we should do it".
Apple has shown that they can do a fairly good job at serving up content with the current little black box. Much of the failings on that front are due to content deals, or rather lack of. Get the networks and studios on board with the pricing, quality and timing issues and much of that is solved. Even things like how those iTunes Extras still don't work on the Apple TV system could be due to studios not wanting them to work on 'tvs' so that they don't take away from disc sales. Make them get over that either by convincing them they are wrong or just do it anyway (like Apple did with the longer previews on music). And so on.
What could making a 'real' TV do on those fronts that the box can't. Nothing. Same with the UI issues.
Apple has a history of leaving things to do those that can do it better and right now that's Sony etc. What could Apple possibly do better than them that would push them to making their own real TV. Can they make a better screen, can they make it thinner, more energy efficient. Perhaps. But making a TV means getting into bed with those other companies over needed patents and that's a big messy to do. Apple's only going to go there if they can make major improvements in the game enough to make it worth it. If they don't have to go there then they won't. And frankly they don't. IF they are making some kind of display item that could be all it is. A display. A dumb display. Beautiful, energy efficient screen. Lightweight size with perhaps even the VESA adapter built in for wall mounting. Couple of screen size options. And the needed inputs for you to hook it up to your computer, blu-ray, Apple TV or even cable box. Beautiful and flexible enough to 'compete' with those tvs without actually trying to compete. And who knows, if they aren't chasing all those patents maybe they can manage something in the 46-55" inch range that's under $3k
Look at this with Apple Eyes based on what they have and are doing and what they say and ask yourself if you really believe that Apple is going to chase this market by copying all the other boys, or by ignoring them to a major degree, improving two markets (tvs and computer displays) at once with one product and keeping the 'smart' in the little black box and their content offerings.