As reported all over the place so far, Brock's next UFC fight will take place at UFC 106 in November, where he will be taking on undefeated Shane Carwin. Never heard of Carwin before? Well, in his 11 matches, he's never taken longer than 1:30 (other than once), to defeat an opponent. While the only fighter of note that he's beaten is Gabriel Gonzaga, But Carwin is a beat. Brock finally faces someone his own size, should be very interesting.
Right now the odds are pretty heavily in favor of Lesnar, but I think it's much closer than it appears.