From July 23 to August 10 of this year (2010), I more-or-less followed the yellow route above from Sao Paulo to Belo Horizonte, Cuiba, the Pantanal, and many points in between. The tour was organized by a British company. The travel group was an eclectic collection of 11 people: 6 guests from Britain; 3 guests from the U.S.; a British tour leader; and a Brazilian guide.
This wasn't my best choice for seeing the wildlife of Brazil. Even though marketed as a mammal tour, it was conducted more like a birding tour where much of the focus was directed at spotting as many birds and animals as possible, often at great distances. As a photographer, this didn't work very well for me. The British company responsible for the trip primarily runs birding tours, so I should have known better.... birders and photographers have very different needs in the field. The first half of the trip was especially disappointing..... we spent hours and hours in a van rushing from point to point with little time to spend at our destinations once we finally arrived. Plus, the weather wasn't great.... often cloudy and quite cold.... and the wildlife was sparse. The second half of the trip in the northern Pantanal was much better. The wildlife was diverse and abundant. I would happily return to the Pantanal to explore that region in more depth.
As for Brazil, we didn't really have the opportunity to get to know the country. However, the transportation infrastructure was great, the food was wonderful, and the people we met were helpful and friendly.