I'm feeling close to the same as many people on here.
About the plasma situation, there's absolutely no chance Apple will go that route. They've always been about saving power; and plasmas are huge power hogs, no matter how nice they are on the eyes (Yes, I have a 60 inch Pioneer Plasma screen.... it is a beauty, but man does it get hot. Although, Apple's TC and AEBS don't seem to be far from the same operating temperature...
). I guarantee it will be either LCD or LED, most likely, LED.
That's only if they do go down the TV Set path.
Overall, I don't see it happening. It would get too complicated having to deal with more service providers and SAMSUNG. Please.
I think sticking to the aTV is Apple's best bet. The only reason people aren't buying it is because of the lack of functionality: no web browser, no apps (other than Netflix and whatnot), no hard drive disk space.That's what also disappointed me on the aTV2 update... no hard drive or 1080p output.
What I DO see in the near future is making the aTV a gaming device. Throw in App support and HDD space. Hook it up with an iDevice and you pretty much have the new Wii. That's what will be the key selling point of the aTV3.