According to the official Jump Festa website the dates for Jump Festa 2013 have been revealed and this event will take place December 22-23rd 2012. Nothing has been revealed for the booths or Super Jump Stage just yet, but that info should arrive soon. However, we can expect to get more news on the DragonBall Z 2013 movie during Jump Festa, even though that is quite a while to wait. So until then, we will have to keep an eye out on any publications such as the Weekly Shonen Jump and the official website to reveal new information and media.
Speaking of Weekly Shonen Jump, issue #42 for 2012 has released and does contain information regarding Jump Festa 2013. However it is uncertain on if any info on the DBZ movie is inside this publication, but stay tuned as we try and find out!
Update: Hujio from Kanzenshuu states that the following information was inside issue #42.
The new Jump Festa website has officially launched! The event will be held at the Makuhari Messe Convention Center in Halls 1-8 on December 22nd through the 23rd from 9am to 5pm each day! Local parking will be available! It will be a festival celebrating the most popular characters from Jump’s four magazines (Weekly Shōnen Jump, V-Jump, Jump SQ, & Saikyō Jump)!