But the 65+ wasn't really a new generation of back. It was a new sensor in an existing generation back with a few new options (e.g. Sensor+)
In my opinion there have been three major generations and three minor generations since 1998.
Major generations:
Lightphase/H series (1998)
P/P+ (2004)
IQ (2011)
Minor generations:
- going from light phase to h series (2002)
- going from p to p+ (2007, added long exposure, moderately better LCD)
- going from p20+/21+/25+/30+/45+ to 40+/65+ (2008, switch to , sensor+ and addition of full frame sensor)
So from that point of view the IQ will be the platform/chassis for 5-6 more years, and a new feature, new sensor, or other minor generational improvement might be seen in a year or two.
This of course is all educated speculation. The past informs predictions about the future, but does not guarantee them.