Time's Mark Halperin has it "confirmed by sources" that the anonymous author behind O: A Presidential Novel is Mark Salter, the former right hand man to John McCain. He's been hiding in Maine, writing this thing!

Who is this anonymous author, with "vast" White House insider knowledge, behind the upcoming O: A Presidential Novel? Publisher Simon & Schuster released more information today! But now it seems more like a hoax.

Simon & Schuster is publishing a book titled O: A Presidential Novel this month, by "Anonymous" — supposedly someone with "vast" insider knowledge of the Obama presidency. Will this be the next Primary Colors? Sure! Unless it's a hoax. [via]