Key features / improvements
21 megapixel CMOS sensor (very similar to the sensor in the EOS-1Ds Mark III)
Sensor dust reduction by vibration of filter
ISO 100 - 6400 calibrated range, ISO 50 - 25600 expansion (1Ds Mark III & 5D max ISO 3200)
Auto ISO (100 - 3200) in all modes except manual
3.9 frames per second continuous shooting
DIGIC 4 processor, new menus / interface as per the EOS 50D