Andy Ihnatko thinks an Apple Television won’t be a full-on TV set, but a significant evolution of the current $99 Apple TV box:

I keep rounding back to simple math: $99 Apple TV + $$ HDTV of the user’s choice from anyplace else > $$$$ Apple HDTV.

But what if it ends up as being both? A $99 Apple TV box a la the Mac mini, and a $1,500 HDTV a la the iMac. Both of them could have the same software and “the simplest user interface you could imagine”, but the HDTV could come with all sorts of hardware perks — such as a built in router with a huge Wi-Fi antenna, a FaceTime camera — and of course it would be the most attractive and high-quality TV set anyone could buy.

Andy Ihnatko’s Apple TV Speculations