Erm... Bring the 70-200 f/2 too and damn I'll buy those two preciousssssssssssssssssssssssssssssssssDoable, I guess, big and heavy for sure, and a filter size of 105mm+. Similar to size/weight of 120-300mm f/2.8 or 200-400mm f/4. Betting now the price will not be less than Canon 70-200mm II if it ever materializes.
Less than the 70-200/2.8? The 200/2 is $5k+ so a 70-200/2 would be more costly and very heavy.