I've got a couple of 20Ds and a daughter in college, so I'm not buying a lot of new camera bodies these days, but I've looked at the 40D and it seems like a major upgrade compared to the 20D in terms of the viewfinder, interchangeable screens, and other features that matter to me because of my use of lots of weird and wonderful older lenses (like my Vivitar qdos anaglyphic 3D lens!). My only problem with the crop was and is that I do a lot of architectural photography and my old Nikkor 35mm Perspective-Control lens is just too long on a crop body. In a sense, for that purpose, I either need to spring for a 24mm TS-E lens or buy the FF body like the 5D. Since I do want to get a new body, I suspect that one of these days I will go for the 5D MkII when it comes out.
Like KeithT, says, these things are tools and what tools you need depends on what jobs you have to do.
Swede
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