Is it possible to convert the in camera histogram display to a film characterisitic curve, thus allowing one to set the camera for example to 'Velvia' and having a truly representative mapping of histogram values for subsequent film camera exposure?
You can't currently do this, but it seems like it should be possible to hack in. The live histogram uses the live view framebuffer, so calibrating it to absolute values might be a bit tricky. Actually taking a shot with the digicam and going from the raw buffer would be another option.
Either way, hacking required