Imagine, a 135mm f/1.4L, four stop IS lens, with fluorite and UD lens elements!
Wouldn't it be great, for those of us who prefer the 135mm focal length for portrait work, to have our own 135mm white lens version of the 200mm f/2.0L IS? I am sure that some sports and wildlife photographers might find this lens appealing as well, especially if it was smaller, lighter and cheaper than the 200mm f/2.0L IS and 300mm f/2.8L IS II lenses.
Now I am not suggesting a replacement for the current 135L lens but, just as the 200mm f/2.0L IS is different from the 200mm f/2.8L II, so would be the 135mm L white lens from the current 135L.
As much as I would love to see Canon upgrade the current 135L and 200L f/2.8 II lenses, with 4 stop image stabilization along with some other lens element and aperture upgrades, I also find something very appealing about a super fast 135mm, image stabilized lens, painted white.