I just thought it would be interesting to go over the many 18-55 models:
1. original 18-55 G ED model from Apr 2005
2. 18-55 G ED II with updated cosmetics but otherwise the same, from Nov 2006
3. 18-55 G VR from Nov 2007
4. 18-55 G VR II with collapsible barrel from Jan 2014
5. 18-55 P with collapsible barrel and stepping motor from Jan 2016
6. 18-55 P VR, same as above but with VR
The crazy thing is, except for the first model, ALL are listed as current models on the Nikon website. Maybe they are still clearing out old stocks of old models, or they really need to rationalise their production - eventually all should go except the latest two models.
All the early models have the standard 52mm filter size. The two new "P" lenses have 55mm filter size - the first time in 65 years of F-mount lenses this size is used. The 1NIKKOR 10-100/4-5.6 also takes 55mm filters. Interestingly it shares the same hood with the new 18-55 lenses.
There is a general trend is for the optical design to become more complex - the latest versions have more elements and two aspheric elements.
I wonder if Nikon will soom introduce compact 55-200 telephoto zooms with stepping motors to match?
The new lenses have been added to my site, along with the D5 and D500