the canon 40D blows the D80 out of the water.
and both those kill the sony.
yep...the D80 won't be able to compete with the 40D in a lot of areas. Can keep up to a certain point and that's it.
I would get a camera to suit your needs. If you are looking at a camera you need to ask yourself a few questions:
why get a DSLR?
Are you going to use the features of a DSLR?
Do you like to control what the camera does in terms of adjusting the shutter spead, F-stops, ISO's?
What type of pictures to you take? Portraits, landscapes, pets, kids...etc. These will have an effect on your body and lens choice.
Are you willing to learn and keep on learning?
Before you look at any of the cameras. Jot down a few answers and start your research from there. I've seen great pics come out of simple point and shoot cameras and yes, you can get really atrocious pics from a DSLR if used improperly.