c|net posted an article about Canon and Photokina 2014. There are snippets of an interview with Canon technical advisor Chuck Westfall.
Concerning the replacement of the EF 100-4mm f/4.5-5.6L, Mr. Westfall said:
“a new model is in the works […]. It’s definitely on the boards for replacement”
However, Mr. Westfall declined to say anything about when we will see the new 100-400mm lens. In the past we saw a patent for a 100-400mm f/4.5-5.6 IS DO lens with diffractive optical elements (DO)
Moreover, Mr. Westfall confirmed that there will be more DO lenses in the future.
Canon is working to spread a technology called diffractive optics, or DO, into more lenses
Finally, the lenses for the EOS M system. c|net writes that “during a press conference here, the company [Canon] committed to adding more [EF-M lenses]” .