Thanks for the quick replies. Here is some more info.
I shoot mostly landscape and wildlife.
I have my first baby on the way and am interested in a low light, fast lenses. The 17-55 f2.8 IS seems like a perfect baby lens, but it only works on a EF-S mount. 5D and 24-70 f2.8 would be great for a baby, but there is no IS.
I was thinking of going with a 40D, 10-22, 17-55, and 100-400. That might break the bank a little, haven't priced it all out yet. I do have a bit of heartburn over buying EF-S lenses. They get great reviews, but I am afraid I treat my gear more roughly than an EF-S lens could handle. I travel 180 days a year and my camera goes on every trip.
I hadn't thought much about the 5D. A 24-70 lens on a 5D would go as wide as my 17-40 did on my 20D. Not sure about the 70-200... I rarely used that focal length on my 20D. I think I would opt for the 100-400 L or a 17-40 L instead. I love wide angle, and I really want to be able to get wider than my my 20D setup went. However, I really liked my 100-400. On a full frame body I am afraid the 100-400 wouldn't be as useful.
Thanks for the replies. Keep them coming.