A lot of people here are saying that their Rebel has the same sensor as someone's xxd which is the same sensor as the 7d, to support whatever argument they're making. I suspect that its just based on megapixels. Just because a sensor is APS-C, and the same number of megapixels, does not necessarily mean its the same sensor.
Part numbers are useless, as the same sensor might be soldered to a different circuit board or changed in some other trivial way.
DXOmark? The 20d and 30d are known to have the same sensor, but have different scores, and some of their methodology is questionable as well.
Does anyone know for sure? Is there a reasonably authoritative source to settle this, one way or the other?