A final word on cost comparisons. I find fascinating all the discussion about the 40d being so much cheaper than the d300. I think the comparison is bogus, even when the talk is of adding in the cost of accessories which supporsedly make the bodies more equivalent. The comparisons ought to be with cost of the lenses (plural) added in that one plans to use with the body. If the person is satisfied with a kit lens, well, yes, there is still a difference that might make a difference to some. But start adding in a suite of lenses that anyone who is serious about photography is going to buy eventually, the percentage difference diminishes very quickly.
Hmm, maybe. But almost all the focal lengths I use regularly are significantly more expensive from Nikon than Canon. Which would increase the cost savings of the Canon over Nikon, not diminish it. (If I consider that I already own a significant number of Canon lenses, the cost difference becomes astronomical.)
Don't get me wrong, I think the D300 looks very impressive, but I don't see very many scenarios where it's even close to the price of the 40D