Según un comentario de nikonrumors.com estas serían las especificaciones, vendo la d3 como esto sea verdad.
NIKON Q2000
Mount: Nikon Q mount
Sensor size: Nikon QX format (19 x 15 mm)
Resolution: 3968 x 3264 (13 Mp)
Burst rate: 8 frames per second
ISO range: 200-12800, plus LO1, HI1, and HI2
Vibration Reduction: Nikon QVR, 3 stops equivalent
F-mount compatible: Yes (Nikon AF-S lenses with RK-3 adapter)
Slots: 1 CompactFlash card slot
Ports: USB, HDMI
Nikon Q400
Mount: Nikon Q mount
Sensor size: Nikon DX format (24 x 18 mm )
Resolution: 4928 x 3264 (16 Mp)
Burst rate: 6 frames per second
ISO range: 100-6400, plus LO1, HI1, and HI2
Vibration Reduction: No
F-mount compatible: Yes (Nikon AF-S with RK-3 adapter, Nikon AF-D and AI lenses with RK-5 adapter)
Slots: 1 CompactFlash card slot
Ports: USB, HDMI, external DC power
http://nikonrumors.com/2010/09/17/what-is-nikon-q-part-2.aspx el artículo completo.