World Scout Jamboree - BSA FAQs:

Q. What are the dates and location of the 23rd World Jamboree?
A. The jamboree will be held in Kirara-hama, Yamaguchi, Japan, July 28 to Aug. 8, 2015.

Q. Will the BSA send only one contingent to the 2015 World Jamboree?
A. A contingent is the entire group BSA sends to this event, and each troop and crew will be part of that contingent. Right now, we are planning on sending approximately 1,600 people as part of BSA’s world jamboree contingent.

Q. Will my Scout's world jamboree leader be from his troop?
A. World jamboree units are formed by region, not council. Therefore, the youth and leaders that make up a jamboree unit will most likely be from various councils in your region. We will not know who the specific leaders are just yet, but your Scout's leaders will also be from various councils in your region....

And many more:

http://www.scouting.org/WorldJamboree/faq.aspx