There us no reason for Apple to enter the TV market. While they may have been dabbling with the idea to see if they can match Samsung in more product markets, the idea of an actual Apple TV set is dumb.
First, Apple can't do anything innovative for TV. They are flat screens that display content, period. Any "innovation" could only come in software running on the TV and if the Apple TV box is any indication of where Apple is headed, Apple has already flubbed innovation wise. I picked up a Roku 3 for my Dad for Christmas and it's light years ahead if Apple TV, I may actually dump my Atv.
Second, this is a highly competitive market dominated by Samsung. If Apple comes out with a TV, Samsung will have 10 competitive sets out within 6 months, all more innovative and cheaper then Apple. Sony and others will follow suit.
Thirdly, there is hardly any margin in TVs. Apple can try and sell a $10k TV, in order to get 300% profit margin they are a custom too with phones and tablets, but TV consumers will not tolerate that price structure. TVs have been around for near 100 years and consumers have been value conscious about TV set pricing long before Apple existed.
Lastly, why limit themselves? People will not upgrade a TV yearly, but might upgrade an add on frequently. The Apple TV box can work on all TVs, even competitors. Why waste millions investing in a stagnant 1% market share when you can invest less in making a product that has a potential for a wider and repeatable install base. All apple cares about is hooking more people into there walled garden, Apple TV as a box can do more as a cheap add-on vs an expensive TV set.
Apple needs to do more with a set top box this year as their AppleTV is falling behind in innovation and a box is all they need to get into everyone's living room. An actual TV will be a huge failure. I mean, what's next, Apple iFridge just because Samsung makes WiFi refrigerators?