I'm about to sell one of my 40Ds and plan to get a full-frame Canon in the near future. I am waiting to hear what Photokina has to say about things, and will make up my mind then. If announcement is made regarding new 5D, I'll wait and get it. If no announcement, no clue what I'll do! I even have my wife's approval on this one!
Good for you. It's not that big a difference - when you look through the viewfinder it's still just photography. Of course, it is fun to take an EF lens, shoot with the 40D, and then shoot the same image with an FF camera - suddenly you understand the crop process really clearly FF is esp. nice with a wide-angle lens, or landscapes.
yeah, that's a big push. I reallllly like the range of my 70-200 on my 35mm camera...now, if that was only digital...
I'd be tempted to wait for the 5D's replacement as well. Although, you should be able to get a good deal on a 5D though. One thing to consider is the fps speed. You shoot a lot of sports, don't you? The 5D is only 3 fps, which feels pretty slow compared to your 40D. I believe the 40D also has a better/faster AF. So I think the current 5D might be a little disappointing for you. You might consider a 1D mk III or mk II. Not quite full frame but a true sports shooter's camera.
Yeah, I like shooting sports, but will likely be putting more emphasis on the more creative side of photography in the near future.