iMac TV?
Apple always enters a market small, builds in some exciting functionality to encourage sales, then adds on in subsequent years to grow the product. Apple TV is a good start as a set top box with Internet and local network connectivity to access anything you want online. The iMac provides full computer functionality, with built-in camera, microphone, speakers, and now Thunderbolt connectivity.
Take this to the next step, add a bigger screen (32" & 37"), build in the Apple TV software (it's already a subset of MacOS X), and iOS apps within the Apple TV interface. Add optical and HDMI (or appropriate Thunderbolt adapters), Siri voice control, and what do you have? A big HDTV screen on an iMac with full Apple TV and iOS app functionality.
Now, say Siri play NetFlix, Siri play game X, Siri go to Apple.com in Safari, Siri (all the regular iOS voice commands, but now with big display to complement voice response). Siri sleep (screen blanks to black). Siri, what's the weather (screen wakes up, displays weather with voice comments). Siri display movie X (plays movie X from iTunes library). Siri FaceTime call Charles... Whatever... Don't want to use voice control, use your iPhone as a controller, or the iMac's keyboard.
In short, a voice controlled iMac using a HDTV screen as a display, running Apple TV in software, with the added Apple TV hardware connectivity.
Now say, "Siri switch to iMac Desktop," and return to normal iMac interface to do routine computer stuff. Limiting the first attempt to 32" or 37" inches shouldn't hinder the Desktop experience.
This capability is already at hand, just waiting for Apple to integrate it into one device. Apple adds in some newly negotiated contracts with content providers to sweeten the deal, which does nothing to threaten traditional TV setups. But, it shows everyone the future of totally integrating the computer with the TV. Apple could even offer HDMI-in to connect your current set top boxes to use it as a regular TV.
This device offers a tempting option for apartment renters, giving them a TV/computer in one box, with 21st century features like voice control and Siri Internet searches. This would also be great in bedrooms and home offices. Once the concept takes hold, Apple ups the game with larger displays for the living room.
In the meantime, Apple TV 3 is upgraded to add Siri, iOS apps, and the other stuff for people to begin to enjoy these extra features with their current TVs. But, the next time they're in the market for a new computer, or TV, the seed will have been planted.
Apple makes money selling hardware, tightly integrated with services through software. If the content providers aren't ready to play ball, there's plenty out there today to tightly integrate all your iTunes stuff, Internet iOS apps accessing media online, online gaming, and all the other stuff you do on your iPhone and iPad today to make such an integrated iMac a game changer.
I know I'd want one.