Past of 40k minis
Citadel eleased thier first miniatuures in 1979 for genral Tabletop use. In 1983 Warhammer 40k 1st edition was released, in 1986 the first Space Marines were released. THis led to the popularity of 40k that we know. From here, around 2007 large advances were made in miniature development technology. THis led to larger and more detailed miniatures.
Condensed History/backround
Currently, 40k is one of if not the most popular wargame and miniature line. Recently, it has been gaining popularity and expanding a lot. We are also having lots of new releases along with a new edition of Horus Heresy this year.
Future
Currently Games Workshop is not releasing new armies, but rather they are continuing to refresh older armies in order to get them to the nw scale. The future continues to look bright for miniatures.