Why would Apple, which aims to turn users into producers, make a boob tube?
Why would they piss off all the companies that make them, when they'll want to work with them?
Why would they make a DVR, when the current ones are marginally profitable and under a more or less continuous legal threat? Not to mention a fundamentally crude and retrofitted time delay, however slicked up.
I just don't see it. Any DVI-capable HDTV already works with your Mac as slickly as it's going to. It's fast becoming commodified, leaving no room for Apple to compete (yeah, Apple uses commodity components, but the platform is not a commodity).
Slick design? Apple's idea of a slick design these days is to make the components vanish so that all you see is the screen. TVs are already there, long since. Integration? How much integration can you possibly do with a TV? I can think of all kinds of cool stuff you could do with a DVR, all of which would bring down a host of lawyers from the entertainment industry—who would win, by the way, unless the presiding judge took the rare stance of proclaiming much the last 18 years of US copyright law unconstitutional (not that I'd mind...). The DVR has even less of a chance in Europe, whose IP laws make the US' look anarchic. And how many people would want to have to buy an Apple TV to get the DVR anyway? What's the point, when you have the functional equivalent of a DVR sitting in your lap?
I honestly don't see what Apple gains from this, nor what we'd gain from it, except for the passing thrill of having one more thing with a glowing Apple logo on it. Mark my words: Steve is going to do to video what he's doing to audio. All digital. No stock, no ordering, no limited selection of titles (eventually!). You download it, you "own" it (in an analogous way to the way you "own" the songs on a CD). This is (one reason) why Steve is pushing HD support in QuickTime so hard. (The other is of course content creation, and you just know he'd like to have solutions from start to finish.)
The TV will still be there, of course, just as the CD is still here. But instead of retrofitting a DVR to a TV, you'd just buy what you wanted to see, and watch it whenever you wanted to. There are still some major hurdles to clear before Apple can do this, but Steve's been talking to the industry players for some years now, and testing the waters at the iTunes Music Store. I'm sure he fully intends to have everyone lined up for when he rolls this out in earnest.