If I were Apple or Samsung and I wanted to own the living room, I'd add HDMI out to my mobile & tablet range, a fancy remote, and sufficient apps ...
An ipad stripped of the screen and boxed has been bantered about. I don't see a huge uptake as the advantage of the ios is in the personal mobility and the apps centered around that personal mobility.
The idea of an ipad dock has also been bantered, but if it isn't connected all the time, how would others watch the TV without your pad being there?
Great solution for the tech gadget bachelor, not so much for everyone else.
Again, I see this going back to a STB of some sort.
AppleTV failed multiple times. Other internet streaming devices have also failed to garner much traction.
The only STB's that have had any level of success are internet enabled BR players (only because the feature is stuffed into a BR player for "free"), cable boxes (necessary for cable tv), and game consoles (again, internet streaming apps for free).
Pretty short list.
I may be wrong and Apple may decide to go AppleTV 3.0 ... but I suspect the venture will not have much success beyond their existing offerings in that arena as it's too little bang for the buck. Especially in the current competitive climate.
The only other angle outside of games console that they could go and hope to achieve success would be to make a deal with cable cos integrating ios into a cable box ... (I've mentioned MS/Sony should go after this market as well).
Such a venture as a ios cable box would provide a substantial boost for cable customers and Apple. They wouldn't be competing directly with Sony/MS and could offer game controllers at the Apple store for playing IOS favs on the bigscreen (on the cheap).
Parents would like it, cable cos would like the edge over Sat TV (or other local provider), and devs would like the increased exposure and new experiences possible with a tv/couch gametype vs the typical short/portable/cheap ios products.