An actual Apple television. More than a few people believe it's on the way. And more than just offering hardware without good content deals in place (BOXEE, GOOGLE...I'M LOOKING AT YOU), it's rumored that such a device would either run iOS apps, play host to a revamped iTunes video subscription service, or both.
How likely this is, we can't say for sure. When previously asked about their move into the living room, Steve Jobs has casually mentioned his dislike of set-top boxes, and hesitance to fully commit to that market (then again, they also announced the latest iteration of the Apple TV after that). Analysts have been speculating. And ever since, rumors have steadily trickled in, regarding both hardware, software, and the much ballyhooed data center in North Carolina (streaming video service!).
But there is certainly a need for a killer IPTV device/infrastructure that can free us from cable once and for all.
On-demand television is bigger than ever, and mainstream consumers are catching on at a rapid pace. However, the vast majority of "smart" televisions have been poorly conceived and executed when it comes to user experience. Which is to say, they're almost all shit. And it doesn't help that companies Hulu and Netflix have been facing non-stop resistance from the old television guard and ISPs when it comes to comprehensive on-demand programming. If one company could manage to pull all this off its Apple. But it definitely needs a few things.
Obviously a top-notch user experience on a quality display panel is what would set Apple apart from the TV makers. It's nearly a given that this would be addressed, but Apple would have to not only create a UI that looks and runs smooth, but also makes searching for shows, movies and video quick, easy and intuitive.
Apple also has ISPs to worry about. TV consumed entirely on the internet raises the problem of bandwidth. On the consumer side, bandwidth data caps are a subject of much discussion as the battle over net neutrality is hashed out. But video services such as Netflix are having to deal with ISPs charging more money to provide access to their site. If Apple was interested in a video service of their own, they'd certainly have to deal with this.
But, as far as longevity goes, content is the most important. Financially speaking, Apple could produce an above-average panel, sell it at a loss, and make it up in content revenue. In terms of consumer adoption, content would help them avoid the fate of Google TV. It had an attractive UI, but nothing worthwhile to actually watch. For Apple, the content conundrum can be approached from two different sides: apps and distribution deals.
If they allow people to download apps, content from Netflix, Hulu, Adult Swim, YouTube, Vimeo PBS, and many other sources would be immediately available. For those who want sports, there are also apps for MLB, NBA and NHL.
However, if Apple goes after television like they did music in the early 2000s (by negotiating their own deals for selling content), they could radically change the way we consume television. The main challenge for Apple is convincing the networks and studios that this new way of consuming television is a good idea, and getting them to agree in a way more favorable to consumers (the whole "available in the browser only" thing on Hulu is the worst). If they can negotiate a deal with ESPN (even if it's just an ESPN 3 app), people would feel much more comfortable getting rid of their cable.
The most exciting thing here is that TV could become customizable. Maybe you get certain quantities of shows or networks at tiered prices (which isn't all that different from how cable works now). But you would have far more control over what you're paying for. And it would all be on-demand! Consumers may not like the idea of having less selection; but if they're choosing from stuff they actually want to watch, how much of a difference would it really make?
More than anything, Apple just needs to find a way to convince everyone that viewing freedom is a good thing.