Relevant portion from the Post article:


Then, on Tuesday morning, the venerated AP Stylebook publicly affirmed (via tweet, no less) what it had already told the American Copy Editors Society: It, too, had succumbed. “We now support the modern usage of hopefully,” the tweet said. “It is hoped, we hope.”

“We batted this around, as we do a lot of things, and it just seemed like a logical thing to change,” says David Minthorn, the deputy standards editor of the Associated Press.

Previously, the only accepted meaning was: “In a hopeful manner.” As in, “ ‘Surely you are joking,’ the grammarian said hopefully