Although I primarily use two Canon 40D's, I am keeping my old, but trusty Canon 10D as a third body. I know, I know..."it's only 6 megapixels". Yet, many images I've taken with it have run in the newspaper at large sizes and looked excellent. Not bad considering that most newspapers are printed on the equivalent to Charmin.
Granted, it doesn't shoot 6.5 frames per second, but I have captured some intense sports action with it. The 10D even works well for very long exposures like this one from Yosemite.
And while it was a bit noisy straight out of the camera, a simple pass through a Noise Reduction plug-in like Neat Image cleaned up the file beautifully.
With the 10D, you can make enlargements up to 16x20 while still holding reasonable sharpness, and clarity
Moving forward, I have some cool plans for the Canon 10D. I'm going to use it as a remote camera at sporting events, and fire the shutter wirelessly with these remotes by Paul Buff. So while I shoot with my two 40D's, the 10D will be capturing images from a different perspective. This can also be used for nature photography, especially with skittish birds or animals.
I've seen 10D's selling on Ebay for as little as 200 bucks. Mine however, will not be for sale.