I'm just travelling around a bit at the moment and I'm unable to format or research these patents thoroughly. I'm sure some of you will tear it apart. A better translation would be appreciated.
This Japanese site has posted some Canon patents he/she has found.
This is a direct email quote
Based on his investigation Canon made following patents.
EF300/F4 IS II with plastic lens.
This would be a welcomed lens by many.
EF70-210/F4 IS II with plastic lens
Not sure this lens needs an update yet.
EF300/F2.8 DO IS and EF 400/F4 DO IS with new double DO and IS
A lot of DO patents popping up. A lot of people ask for smaller and lighter lenses.
EF 15-24/F3.5-4.5 Fish eye zoom (not EF-S)
I think this would be a great fisheye solution. It wouldn't cost a lot at first sight.
All make some sense outside of a new 70-200 f/4L IS.
View more lens patents here