>even full game streaming doesn't use that much bandwidth, and
>it seems unlikely that's what they're doing.

I know what the fuck I'm talking about, nigga. The internet is a series of tubes and if there's too shit passing through them they get congested.

Seriously, though, I'd put 3 to 1 odds on Xbox Live having a Simcity-style meltdown during the week of the 720s release.