Dave:

Do you shoot from a tripod much? If so, then there probably is not a real good reason for the 24-105. However, if you are hand holding the majority of the time, then it may have merit. I love my 24-105 (even on a crop body) - I realy like the IS when hand holding... but since I am on the tripod mostly, I would much rather have your FF 17-40 and 70-200 combination than my crop body with 10-20 and 24-105 combination. But if I was hand holding I would seriously consider the 25-105 because it is so versitile and covers a nice range.

I would not get hung up on getting it because it is cheap if you do not need it. Personally, I have enough to do without selling equipment I do not need.

Enjoy your new camera.

Pat