With most lenses becoming better all the time ... What is your opinion about future update circles ? Will Canon replace its highly successful EF lenses e.g. the 11-24, 70-200 IS II, 24-70 2.8 II or the gen2 Supertelephotolenses again in some years or do you think there is not much to gain in IQ anymore with the top of the line EF lenses and therefore these will stay for another 15-20 years before they even think about an replacement ...

This more a general question about the length of update circles, so please please stay general and don't break this down into things which might only apply for one or two lenses ...