I am comparatively new to the area, so my experience is (very) limited compared to the others.
I do know that the sharing of information via the net has helped expand ideas, drive standards and share techniques.
I remember painting some cast metal figures for a cannon set, I thinking 25mm high. No facial detail, very limited in other details. That would have been 20 odd years ago, now
I also remember painting up an entire box of 1/72 airfix (?) Waterloo British regiment. In enamels. Nice detail, hard plastic.
Nowadays, Acrylics are the in thing, yet a quick 10 minute search here will reveal great results using all mediums, or even combos of.
And the details in figures has increased hugely.....
As for models, movies and miniatures, I would check out the American markets, which (to me, at least) seem to have a thriving culture of horror, comic book heroes and villains, depicted as busts and figures.
Cartoons and related, the third Transformers film is due out soon, so take a walk through your local mega shopping complex, and you can see the tie-in "must haves" toys done in plastic. Then see the age ranges and genders buying..... either young boys, or men who saw the cartons first time around, and getting them for themselves and/or their own kids. (Or both)
Searching out Star Wars figures would be an interesting data set too..... Some would say that dear old George started that whole trend off....
(On a personal note, the re-pops of the figures when re-released, looked far more muscular then the originals- but that partially personally opinion, and partially a sociological phenomena)
Japan Anime and figures, there is another whole new area, and hopefully Kazufumi-san can add some insights. Now there is a relationship between media and figures.
with in western media, miniatures seem to be associated with characters of evil. CSI did a season with "The Miniature Killer", and one of the James Bond Films had on of the bad guys with miniature scenes from Gettysburg. However, these are two examples, and very limited in scope. I am not implying that we are either serial killers, nor evil masterminds...... Quite the opposite, actually.
While most of the above is not directly related to our field, they are related, probably as precursors to our field.
Anyway, thats my two bobs worth...
Cheers