I have a 40D now. As a general rule I don't think I am going to invest the money to upgrade it until it dies. (though if money allows I might change my mind on that).
However, I am going to Yellowstone this summer. Does it make sense to rent a 7D for that trip, so that I can maximize the photo opportunity?
Does it make sense to travel on such a trip (my second time to this once in a life time trip.. though my first in the digital camera era)... with a camera I have never used before? Is it close enough to the 40D that the learning curve won't effect the outcome?
Or... is it more work and money than its worth, ride to 40D and not worry about it.
My shooting style. I expect to be mostly on tripod for long shot wildlife. Birds in flight and action are what they are, I get them if I can. Not sure why I would desperatly need the high frame rate. Obvioulsy it will be all outdoors shooting, with the only high ISO needs are early morning sunrise (not very likely I would be out that early) and sunset.
Extremely unlikely that I would print anything at all, much less anything larger than 8x10, I don't sell (though I would be willing to take donations).