This is interesting, but I don’t have any video out accessories to test it on.
You just need to add a boolean that says
display-mirroring: YES to the model plist (
K48AP.plist for first-gen iPad) under
/System/Library/CoreServices/Springboard.app/ and reboot the device.
Obviously this requires a jailbroken iPad for you to access the file. It also seems to work with devices that use the A4 chip.
I guess this is how Apple did their presentations all along, at all of these iOS device unveiling events. It’s just that now they opened up the hardware to the public (and indirectly, the configuration parameter).
Update 17-Oct-2011: Updated URL