I am considering the 40D. I have a 30D and like it just fine really. The 2mp difference means nothing to me, and as far as I can see the IQ is pretty much the same. It's the live view that I want. Is it really useful for macro and walkabout stuff? It's hard for a guy my size to hit the deck, or bend over for macro work. A live view screen would really be nice. But I wouldn't bother if it is more gimicky than useful.
Thanks!