The way it works is, a jury picks three finalists and then the board votes. This year's finalists were Train Dreams by Denis Johnson, Swamplandia! by Karen Russell, and The Pale King by DFW. (I can't imagine that last was a good book, and know nothing of the other two.) No word whether the board had a hung vote, hated all three, or just what.
... Hung vote, it's said:
"The main reason (for the fiction decision) is that no one of the three entries received a majority, and thus after lengthy consideration, no prize was awarded," said Sig Gissler, administrator of the Pulitzer Prizes. "There were multiple factors involved in these decisions, and we don't discuss in detail why a prize is given or not given." * * *The board has 20 members, including such luminaries as Thomas Friedman (himself heavily favored to win Wanker of the Decade) and a co-founder of Politico - heavy with newspaper editors, which perhaps suggests part of the problem: a single board that evaluates journalism, fiction, poetry ....
Susan Larson, chairwoman of the Pulitzer fiction jury, stressed that it wasn't up to the jury to select the winner. Rather, she said, its job was to submit three finalists to the board. "The decision not to award the prize this year rests solely with the Pulitzer board," she wrote in an email to the AP.
UPDATE: Aaaaand it's Friedman.