Improved Image Quality
The D2x will "pre-condition" each color before converting to digital. In simple terms, D-SLRs have a problem where not all colors start out with the same amount of signal, because the color filters are of differing strength. This often results in excess noise, especially in the red channel, and in odd colors because the red channel in particular has to be hugely (2-3 times) multiplied by the digital circuitry or your Raw processor. By tweaking the color signals while in analog Nikon hopes to circumvent some of these issues. Of course for Raw purists this will raise the question of whether their "raw" file is truly what the sensor sees, since the camera circuitry will be manipulating it before it is converted to digital and written out. Nikon provides this snazzy image of the pre-conditioning process:
Full Nikon Press Release
The camera has a 24mm x 16mm (not full frame--1.5x focal multiplier) sensor. But it also has a unique "high speed cropped" mode which allows it to fire at 8fps using a 6.8MP section of its total sensor, which in turn has a 2x focal multiplier.
The modes feature resolutions of:
Full Image: [L] 4,288 x 2,848-pixel / [M]
3,216 x 2,136-pixel / [S] 2,144 x 1,424-pixel
High Speed Cropped Image: [L] 3,216 x 2,136-pixel / [M] 2,400 x 1,600-pixel / [S] 1,600 x 1,064-pixel
Because the sensor is "DX" sized all current Nikon lenses, including DX, will work with it. If Nikon can deliver sharp images at 12.4MP with this less than full frame sensor that will be a real boon to those falling in love with DX lenses. In turn, for focal length junkies the 2x multiplier effect in the high speed crop mode will be very appealing. Yes, it is similar to cropping the image in Photoshop, and no it doesn't really multiply the focal length by 2, but it sure feels like you have a lot of lens when you use these multiplied focal lengths.
Nikon is promising availability for "Winter, 2005", which of course we assume means this winter, but clearly not December.
Full Official Brochure & Specifications