The same things he reads into regarding the TBA rooms would most likely be 3rd Party Siri Support sessions.
Especially since it seemed like Tim Cook was very much hinting in that direction regarding widening Siri's functionality.
The only thing that doesn't figure into that is Gruber's mention of the ADA. Which actually does strengthen the TV idea.
Still, I don't see what Apple has to gain from rushing into TV. There were Apple Phone rumors for a few years before Apple came out with the iPhone. There's no way they will be late to the party -- Google TV isn't even close and there are already so many contenders. Why not take the time to perfect the platform (which is what they're doing with Apple TV) and the time to hone Siri (Which is what I think they will be doing now) which will likely be the primary Apple TV interface?
I'd prefer to see an Apple TV in another year; Much prefer to see 3rd party Siri services, improved Siri performance, and a wider Siri roll-out among apple devices this year.