It is shame this is becoming a US vs. Brazil issue.
Believe me, Hillary is not going to visit any country without a very good briefing of every potential issue and conflict. She is well aware of the Sean case and has spoken publicly about it. I think she will be careful but she will certainly put some pressure in Brazil. But seeing Jose Dirceu's blog, I think she is going to be faced with opposition within the government.
Brazil's ego is high right now, they think they can "show the middle finger" to the US, but things are going downhill a bit economy-wise, they cannot give themselves that luxury.