I have a press release from Chicon 7 informing me that London is the only officially registered bid for the 2014 Worldcon. This doesn’t mean that it has won yet. It is still possible for a write-in candidate to sneak in at the last minute. However, the chances of this happening are vanishingly small. Even if someone were to start a campaign, it would still be very hard for a write-in to beat a candidate that is named on the ballot. You can start making your travel plans now.