Slipstream was coined by Bruce Sterling in the fifth issue of the important magazine SF Eye in a seminal article. His initial term was novels of postmodern sensibility but he agreed that it did not look very catchy so he came up with slipstream, sort of based on mainstream. As he rightly predicted it hasn’t really caught on but it definitely defines a genre – namely that area between science fiction and literary novels, i.e. science fiction novels that look a bit like literary fiction and literary fiction that has science fiction elements. Sterling has a list of those authors/works in his article and so do some other sites. I don’t necessarily agree with their choices but I like the idea. Some of these, of course, overlap e.g. with magic realism and post-modernism. The highly polemic Instertitial Arts movement seems to have taken over this concept.
Science Fiction and the Slipstream
Christopher Priest’s top 10 slipstream books
Where Does Genre Come From? (about slipstream, which he calls interstitial fiction)
Interstitial Art (I still prefer slipstream; also includes other art forms)
Council for the Literature of the Fantastic (it’s not slipstream but it’s related)