They've been gone since the 80ties - more or less, but prepare for their comeback: leggings.
What we have seen during the past few months was a strong trend of greyish cloths and dresses combined with black opaque pantyhose (more on the side of tights) and heeled boots. Now as the days are becoming colder, the material is getting thicker and the trend is transforming into a shift towards leggings and tight jeans.
Started by the disco and outgoing types of girls out there, glossy or patent leather like versions with a latex like look were first. In an attempt to track down the origin, many traces lead to American Apparel's Shiny Legging, which catwalkqueen resisted to wear out public back in 2007 (same here). Another trace, discovered via f&art, leads to designer Hussein Chalayan who had shiny materials in his show (see the complete collection here) back in February 2007. Since then, f&art has done much testing to this style and seems to like it.
Today, with the trend in full steam (wet-look, wet look or oil-slick leggings are the keywords here), over early adopters like cutesygirl.com with their AERON or MAIDA, even Zara, ASOS, etc. have them. But the the palette is getting increasingly wider and calmer - mainstream, introducing colours other than black and silver through Burberry style check patterns and animal prints. See the first photo on face hunter's realm or this one, this, this to see how people are wearing leggings and wet look leggings in the real world.
More wet look blogging: fashion cereal, et al.