4th Gen Apple TV Release Date?
My guess for the 4th gen would be late 2013 or early 2014 mostly since Tim Cook began at Apple product cycles seem to have shrunk considerably. I don't have the data to prove that, but it sure seems that way when you think of the iPad and Mac updates. It's not something I'm excited for. The new watch, (iTime) is the next i-something product I'm excited for.
A physical Apple TV still seems like a unicorn. It would easily be $4000 or more so the two products would not be similar in my mind at all. It could also suggest that Cook is simply trudging along and doing what the market expects (think iPad mini), instead of challenging the market with true innovation. Do people even like smart tvs? Do you want a new tv? I would suggest against it if you already have a HDTV since 4K is less than 10 years away. Also, integrating a set top box into a tv sounds good, until you realize that in two years or more the tv software/hardware is outdated and you're much better off buying something like a Roku because you can always buy the next gen and it's a much smaller upgrade fee.
If you are interested in an Apple TV, I would suggest to grab the 30pin to HDMI adapter and get along HDMI cord if you need. If you have an iPad or iPhone the Apple TV just lets you mirror what's on your screen, whether it's a streaming service, photos or home movies.
This is coming from a Roku 2 owner so maybe I'm a bit biased. If you're going to be playing music on your tv thru Airplay, an Airport Express may be a better idea because you can also use it for wireless printing. (Don't use it as a router tho, it sucks for that in my experience.)
If you just want a way to watch Netflix and such on your tv, there are cheaper alternatives that are more versatile that the Apple TV. Blu ray players, Roku, a long HDMI cord from your laptop and the 30pin to HDMI cord I mentioned earlier all come to mind.
I currently have a 30pin to hdmi connector which I use to to stream from Plex installed on my Mac Mini downstairs. The main selling point of the Apple TV for me is simply not having to get up out of bed to change the show I'm watching. I'd obviously take advantage of the other Apple features but in my case that's the main reason I want that over the 30 pin to hdmi connector.