In fact, it sounds like the tournament is actually starting on the live realms themselves -- CGS says that they're going to invite the top 1,000 Arena teams from North America and Europe, so if you're one of those, you can probably expect an email with an invite. The actual tournament takes place in June, with the finals in Los Angeles on July 19th, and the winner netting a $25,000 purse. The second place team gets half of that ($12,500), and the 3rd and 4th place teams will each take home $6,250.
Nice work if you can get it. Good luck to everyone out there.