Just Dance 2014 was leaked on the Xbox Live Marketplace via a listing that is no longer available to be viewed.
According to a user on NeoGAF, this is title description that accompanied the title:
The latest opus of the Just Dance franchise will make you dance even more and will be once again the ultimate casual rendezvous of the year. This new opus will be even more social as you will be able to connect and dance with players from all over the world and share a unique dancing experience with them. It becomes the party expert and features today iconic pop culture references. New modes will be available, letting you and your friends experience parties the way only Just Dance knows how!
The series is very popular with it being announced in January 2012 that Ubisoft had sold over 25 million copies of Just Dance games worldwide and the Ubisoft CEO CEO Yves Guillemot proclaiming it to be the twelfth best-selling brand on the current generation of gaming consoles. You can see if the game gets officially announced at Ubisoft’s E3 press conference at 3pm PST/ 11pm in the UK.