AppleTV not going anywhere...
This is probably temporary, and by that I mean this product will be discontinued. They're obviously working on the new Apple Television which will eventually replace the Apple TV.
Not likely. Take a poll amongst your friends / family, I can virtually guarantee that nearly none of them buys a new 1,500.00 - 2,000.00 TV every year when the new model comes out.
Most people buy a TV and keep it for at least 10 years, maybe even longer, because there's simply no compelling reason to upgrade. Unlike a computer or an iDevice with their yearly increases in processing power, allowing us to do more with it, a TV's job is simply to show us stuff. Once bought, with proper care, it'll keep showing us stuff for 15-20+ years.
Sure, lots of people are currently upgrading their old tube TVs and RPTVs with the new LCD flat panels but once they're bought do you honestly expect people to go "Ooooh, Apple's new shiny TV! I totally have to junk this perfectly fine 60" 1080p LCD LED panel I spent 4 grand on 5 years ago so I can have easy access to the iTunes store from my couch (which I already have with my iPad and AppleTV via AirPlay)."
Not saying Apple shouldn't release an AppleTV TV, my perfectly fine 1080i RPTV is close to 10 years old and has some burn in around edges (not to mention crazy overscan) so I wouldn't mind replacing it and if the AppleTV TV looks good it'd definitely be a contender. But realistically its going to be a niche product, kind of like the Macs are now (notice how the iDevices are an overwhelmingly large part of Apple's business), because even with a kicking interface people aren't going to be rushing out every spring to buy a new AppleTV TV every spring.