From my G+ post: https://plus.google.com/u/0/117788095721240811664/posts/gurPTpYzMGm
The problem is: if you have a general-purpose computer doublying as your TV set, the interactions for some computer-like usage scenarios become a lot harder:
Have you ever tried to type on a full keyboard standing on your lap on a common sofa, or worse to mouse-around with no plain surface or having to stretch your arm to touch on a far away big screen, not even Siri can help you while you interact with office suites, drawing programs, email clients, sophisticated web apps/sites, and other high complexity applications.
You really need simpler more focused apps, like you have in mobile, to work in such a configuration, and that is the whole point, it is really software that is holding up the "Convergent" (to use the old word) TV+Computer.
We need a base platform that uses news interaction mechanisms like Siri, Kinect, remote touching, etc... And more focused apps to exploit those mechanisms to bring it truly to live.
I'm working on it, as many others, but I don't think even Apple can really make it happen in the next year, and I would say it could cause a bad 'First Impression' to launch a not up-to-the-task device...
Commenting on a Chris Davies post citing Apple TV-enabled iMac tipped for 2012 television attack - SlashGear