"It didn't go away completely—one still finds oozy, yucky toys on sale and green goop on certain shows for kids. (Kobe Bryant got slimed on Nickelodeon last week.) But I'd submit that 21st-century slime is just a trickle of its former self. The marketers for the Ghostbusters remake will try to sell us slime again: in slime-filled Twinkies, for example, or rebooted ecto-flavored green Hi-C. But slime may simply be too slow and viscous for the modern world."
Daniel Engber in Slate offers a cultural history of slime.