They were expecting up to 1800 competitors i believe and you can see by the depth of the black belt field, this is almost at the level of the pan ams or brasilieros now, very different from the first few in scale from 2004/2005 (albeit 2005 had the jacare/roger match).
Brackets here: http://www.ibjjf.org/cgi-bin/montachaves.asp
Some of the big names at black belt -
Ary Farias, Bruno Malafacine, Leandro Martins,
Bruno Frazatto, Gui Mendes, Rafa Mendes, Ryan Hall, Justin Rader,
Lepri, Langhi, Durinho, JT Torres, Bob Esponja
Vitor Estima, Fin Fou, Claudio Calasans
Sergio Morais, Braulio Estima
Bernard Faria, Leonardo Nogueira,
Bruno Bastos, Lucio Lagarto
Also some elite women competitors too: Beatriz Mesquita, Gabrielle Garcia, Luanna Alzuguir, Michelle Nicolini, Kyra Gracie, Leticia Ribeiro.