The rumors have been all over the internet about successors to the Canon EOS 40D and 5D. I've had many calls asking me what I know, but in all honesty, Canon runs a pretty tight ship and we rarely (if ever) get advance knowledge about new cameras. But this one is official... The Canon EOS 50D.
Just a quick idea of the improvements - This camera boasts a 15.1MP APS-C CMOS sensor, the new Digic 4 processor, a super high-res 3" screen (4x the dots as the 40D screen!) and a new Peripheral Illumination Correction (to compensate for vignetting in lenses). It is our understanding that this is not yet a replacement for the 40D, as that body will continue to be available through the end of the year.
We are officially taking orders on our website as of today. First-come, first-serve, with updates to come as we get an official ship date or other information. DPReview.com (which should be in every photographer's bookmarks tab if it isn't already) has an in-depth hands on preview detailing every new feature from the new Digic 4 processor to the new graphics fade effect on the menu screens.