KenjiS wrote in post #14629321
It has to be coming...
The 100-400 IS is one of the oldest IS-equipped lenses in the lineup, in fact i think it is actually THE oldest (only the 300mm f/4 is close..) and optically? its not the best lens around (its OK but it definitely shows its age)
Its the one lens that could benefit most from an improved IS system...
The Sigma 50-500 OS while not QUITE as sharp (Very very close) in my opinion is a better lens before the 4-stop OS gives a MUCH better keeper rate over the 100-400's antiquated system...
I agree the 100-400L could really benefit from an upgrade, but the rumors have been out there way too long for me to get excited. If Canon finally does announce something, I will be very interested in upgrading if the price is not outrageous.
Until then, I will happily continue using the existing 100-400L. It's probably my 2nd most used lens, and it takes much better photos than a rumor. 