I belive that you are refering to the Bayer CFA (color filter array) when you say that all cameras interpolate and while thats true, that is for color. Nikon uses a different color fiter array from the standard Bayer Method. Nikons system emulates a 3CCD system on a single chip. They use Microlenses over their photoreceptors. The wavelengths of light are seperated to their specific photorecptors red, green, and blue. This system also reduces the loss of light compared to the bayer CFA.
Correcting my previous statment. The EXR has elminated interpolation in some modes but does sometimes use it for others(rare).
"In high DR mode it groups pairs of sensors and uses one of each pair in a higher ISO mode in effect taking 2 x 6MP pictures at once one at higher ISO and the other at a lower ISO and then
doing a HDR merge of the result to get the HDR images at 6MP".
The Super CCD EXR doesnt change ISO modes. Half the pixels are read out during exposure, and the remaining half at the end of the exposure. Compared to using low-sensitivity photodiodes in their
older designs which was used to reading data off the sensor twice.
I am not saying the EXR sensor is not a good sensor. I just hate that Fuji has been putting out their unfinished SuperCCD sensor and basiclly beta testing it on the public since 1999. The SuperCCD HR and SuperCCD SR kindof pissed me off. I guess Fuji just left a bad taste in my mouth so to speak.
In the end I am more excited about Sony's 'Exmor R' back-illuminated CMOS and would rather see this chip in next generation nikons over fuji's CCD chip.