Naboomagnoli
Newcomer
The Wii definitely isn't calibrated to the screen. It is calibrated to the emitter("sensor" bar). By that you could say it knows roughly where the screen it, but it knows nothing of the screen dimensions. You can't actually point the remote at a specific spot on the screen and expect the cursor to be placed accordingly. It is all based on position relative to the sensor bar.
My assumption, which I'm very confident of, is that the PS3 motion controller will be essentially exactly the same, except everything will be calibrated to the camera. Maybe it will ask you how big your screen is, what the aspect ratio is, how many inches the camera is positioned in front, behind, above and below the tv, but I doubt it.
Would that be so difficult though? It would only have to be a one-off calibration in the XMB and that's it, every game using the PSmotes would be calibrated. It could even take a picture of the room at that time and check whether the edges have moved, meaning the calibration may have changed and it could prompt you to recalibrate or carry on.
Maybe we should just move back to CRT's?
As long as Natal doesn't have the resolution to deal with finger movements, I just can't see it performing the same tasks as the WMP or PSmote without using some sort of additional control mechanism. The writing demo in the PS3 demo was not only of smaller wrist/hand movements than you'd expect from waving your wrist around in Natal, and with instantaneous feedback, but (crucially) with the ability to quickly and easily take the 'pen' off the 'page' between letters.