Some years ago, I think it was in early 2009, user Claudomiro imported IBGE highway data under PD license. At that time the Brazilian map was mostly blank, and except for a few, relatively small geographical areas, no high resolution imagry available. The import was welcome by the Brazilian community as it helped connect the dots (the areas with highres and/or active mappers) into one grid.
Now, in 2012, a large portion of Brazil is covered by high res images from Bing, more detailed imports have been done, the community have grown, data quallity in general is getting better.
With this improved data it has been noted that the IBGE imported data is of very low resolution, and some places deviates from the actual path by quite a large distance, users have at random basis corrected these paths until resently, when another user, Vitor Sessak (vitor1234) took the initiative to create an extract with the unaltered nodes of Claudomiro's import , and by an idea spurred by me we have started a (Re)Mapaton in order to get these last roads aligned as best we can.
Of corse I started out in Northern Espírito Santo where Bing coverage is quite good (some holes still missing though), and some alignment already done by GPS and other sources. Litoral South Espírito Santo is already fully aligned. The Caparaó region of Espírito Santo will be tricky to align as highres imagry is almost completely missing, and few gps tracks available.
For other states I havn't turned my attention yet, but seeing on the archive  I see that Minas Gerais, São Paulo, and Goias among other have a lot of non-aligned data.
If there is anybody else out there wanting to take part in our IBGE (Re)Mapaton, download the mentioned file, open it as a background layer in your favourite editor (I use JOSM for this), browse to an area with non-edited points and compare it with Bing, readjust the road if nobody else already have done it and upload your changes.
Vitor have said on the mailing list that he will update the archive, though it is not confirmed how regularly he will do so. The suggestion was weekly updates.
As the road network of Espírito Santo is improving I am thinking about making a complete list of ES-roads on the wiki, and create relations for at least all long and important ones. A complete list of BR-roads in Espírito Santo, and as well all of Brazil already are on the wiki, and most relations already have been created.
If you find my location strange, I am on Roncador oil field in northern part of Campos Basin off the coast of Rio de Janeiro, in the visinity of FPSO Frade (Chevrron/Frade oil field), FPSO Brasil (SBM for Petrobras), FPSO Petrobras 52 and FPSO Petrobras 54