Jon, you are absolutely correct that I do, effectively, have the same reach as I did with my 20D. I'm just getting used to the wider field of view I have now, but I can crop to my heart's content, knowing I canstill get a decent print in the end...
George, your minimalist kit is somewhat similar to mine, I basically carry the 5DII with a 24-105 and the 100-400 to have a pretty good range. I should consider carrying the 500D as well....