R.L. Stine regularly posts news and updates on his upcoming books, TV-shows and movie / -series en and movie(s) on his Twitter page.
Several days ago he posted a Tweet mentioning the title of the latest Goosebumps
book he's currently writing:https://twitter.com/RL_Stine/status/440554345365393408
"Nightmare on Clown Street
" - I guess some terrifying, evil clowns play a huge part in this.