Well, just like for many modern phone OSes (e.g. iOS for example in some cases), you're not able to finish the setup wizard and start using it without connecting it to the internet for inital activation.
I've seen a single Samsung TV up until now, but it was a rather non-common model. Luckly (FOR NOW!) vast majority of TVs still work offline.
In the future this may change - at this point some Samsungs already overlay their ads on volume change UI (and some other parts) to get additional revenue. With such incentives, I'm worried just how long you'll be able to buy a TV that can function offline.
