According to some discussion and photos I found , 40D may be weather sealed after all? Or at least partially? It is a good news if it is true.. and seems like it's gonna have a newer shoe-mount just like 1D mark-III to mate with 580ex II for better fit and sealing.
Looking at these pictures from the Northlight site . it does seems to have some sort of weather sealing .. around the buttons and the new hot-shoe mount .. just like 1D mark III..
Lets wait and see..