The Mail Online claims in an article published earlier this morning that Bond 24 will start filming around this time next year for a 2014 release. The article also claims that Neal Purvis and Robert Wade, who have been screenwriters of the Bond films since The World Is Not Enough (1999), have decided to call it a day.
Instead, John Logan, who was brought in by Sam Mendes and Eon to brush up their script for Skyfall, has been hired to do the job; in the early summer it was announced that Eon was looking to sign writers for Bond 24, so this does appear to fit in. Of course, many things can change; Peter Morgan was hired for the first screen treatment for Bond 23, but his work abandoned when Sam Mendes was brought on board to direct. In an interview Morgan said that he understood that a plot device from his treatment was being retained, but nothing else.