From his twitter feed:
In my office I recently found eight @StephenKing typescripts (IT, MISERY, THE DARK HALF etc.) that he sent me in the 1980s. I forgot I had them. They're going to be auctioned to help children's cancer research.King has agreed to sign the manuscripts. Some of them contain annotations by King and some may represent versions of novels that are different than the published books. Stay tuned for more details as they become available.