Horses for courses indeed ... 7D and 5D are aimed at 2 complete different ends of the photography spectrum and if you can afford it they make perfect partners! (There are certain things even the 5D mk3 won't be able to compete with 7D with and vice versa) Some might argue if you can afford both maybe a 1D MkIV is a better choice but really it all boils down to your actual needs for the camera (Personally I'll definitely prefer having 2 bodies with 2 lenses mounted than having one pro body and having to swop lenses ... unless I win the lotto off course!)
As far as the pop-up flash is concerned I honestly don't understand the hostility towards the lack thereof either, if you can drop 25k on a camera that basically guarantees you the best IQ possible why ruin everything with a popup flash? Yes, it's convenient but it mostly gives terrible results (although I have to mention things are getting better if the Nikon D7000 is any sort of indicator for future trends) ... don't be a cheapskate and just add a 430EX and get it done with! (you can get the 580EX later since that is also a must have!)
just my worthless 2c
Edit: Crap, I really need to learn to refresh before posting, my post just dangles here in mid-conversation (like a bushman scrotum) adding very little value
