First, everyone is just guessing. these Apple Television rumors aren't even linked to leaks about new hardware prototypes out of Asia. which makes them dubious.
Second, the key to each Apple innovation - starting with the Mac long time ago, then the iPod, iPhone, and iPad - is to reinvent the UI of an existing complicated product to make it truly user/consumer friendly. which does require some hardware innovations too, and also new market concepts, but it's all built around the new UI.
Third, Jobs has pointed out how bad the UI is today for all television related products. the tedious on screen cursor menu first invented back in the days of VCR's, and an IR remote control full of confusing buttons (a stripped down version of which is still used now by Apple TV).
so if Apple is going to enter the television business, it is going to reinvent this lousy UI, and then design the hardware around the new UI. so:
(a) the direct path to a new UI for Apple is to turn it all into an iOS app, to run on your iDevice. no more IR candybar remote.
(b) the direct path to hardware for this is simply to build the guts/ports of Apple TV into a Thunderbolt Display. with some larger screen sizes of course, and at competitive high-end price points.
but (c) the direct path to a new market concept for this is the hard part. you would still need a cable box or some equivalent to access much of the popular content.
Apple could come out with an (a) + (b) Apple Television very soon, yes. but without (c) it would still be a "hobby" product. a much better UI than today's Apple TV + any television, but not a disruptive innovation that will change the industry.
so until Apple can solve (c), i think all these rumors are not going anywhere.