but at that point, the presence of a camera at all is a problem, right?
To a certain extent, but there's a difference between a camera that might be there and might be online and one that is almost guaranteed to be there and online on a userbase of, if they pull 360ish sales numbers, about half a million in the first month. It's a more attractive target from a company that has never had the consumer's best interest in mind. I'm suspicious of them and I'm suspicious of their security. As for physical switches, eh, I like my USB camera for that reason. When I'm done Skyping I'm done recording, but I can still watch movies fine. Fine, I'm paranoid.
so, why does it matter at this point whether the camera is intended to be always on or not?
Because then it's there from moment 1. It's not a separate purchase where you go out and buy the camera and mic, and plug it in or unplug it as you need it (or not if you don't care), it's just there. It's not a fringe option, it's something that anyone who can get code on the box can rely on to be there and ready to go, whether they're legitimate or not, be it a misunderstood utterance innocently triggering some social network sharing function or some creep getting his rocks off.
this really seems like a vanishingly small number of cases...
It's not likely, I admit. But just because I'm not likely to get robbed if I forget to lock my door once doesn't mean I should never lock my door. It's getting harder and harder to maintain one's privacy in our connected world, and I don't like parts of the digital privacy fight pushing their way into the real-world even more than they have. I haven't tried to get the government out of my bedroom just to invite some other faceless entity in and pay for the privilege.
and there is a very simple solution anyway: 0.5" of black tape. done.
Unless it suddenly decides that its inability to see is a problem and starts throwing errors because, hey, it's always on and should always be seeing something. It's too soon to tell that of course, but I don't like how this is shaping up.