The 50D boasts 15 megapixels shooting at 6.3 frames per second. Digic 4 processors allow 60 jpgs shot at this rate before the buffer fills. There is also now integrated vignetting correction built in to the camera.
Additionally, it has an upgraded 920,000 pixel 3" LCD perfect for using its advanced Live View function with Face Detection mode. Standard ISO shoots up to 3200 (and looks pretty good doing it) with expanded ISO to 12,800 allowing for low light shooting (but doesn’t look good doing it). Auto-metering is also improved with a 35 zone system linked to the focus points.