A $300 million dollar Powerball ticket showing up in my wallet isn't outside the realm of possibility, either.
Many of you people don't seem to understand business. Thinking that Apple would take a $600-$800 product and combine it with a $300 product is foolhardy to begin with. Particularly when those products fill very different niches in Apple's marketing scheme.
I know, I know... it's so easy to say "hey, they're almost the same size!" without having a clue as to which markets the two products are aimed at. In the same way, it's easy to say "hey, they're almost the same price!" without understanding that they are not. People also assume that ATV is a success, when so far it isn't.
Then there's the killer assumption--that ATV buyers and those that buy Minis for home theater use them in the same way. I'm a tiny bit of a home theater nut. Just a tiny bit. I've got an HD projector, 92" screen, nice audio system. The basics, in other words. Feeding all of that is a ReplayTV, an Xbox 360, an HD receiver, and an ATV. I've got a nice home network, with a file server. Why on Earth would I want a Mini in my HT rack? What I want is to get away from DVDs and loose media. So I've ripped my DVDs onto my server. The ATV has optical and component outs, which is perfect--I don't have to waste precious HDMI or VGA connections as I would with a Mini. Using a Mini to stream movies from my server would be overkill. It would also be an unnecessary complication. For me, the ATV replaced Xbox Media Center. ATV isn't a perfect replacement (not even close), but it has a charm of its own.
My guess is that those arguing that the Mini and ATV will converge don't understand profit margins, aren't home theater enthusiasts, and haven't really given things much thought. Those are just my assumptions, however. I assume about people who make what I think are silly assumptions derived from a lack of knowledge or experience (ignorance is the right word, but that upsets people).