Corinthians managed to keep their better players, plus they've signed Ricardinho from Santos... if Roger and Mascherano get back well from their injuries, the team will be challenging for the title, though maybe they need someone better as a GK (Fabio Costa is gone, the starter is a 20yrs old guy. They did sign Johnny Herrera though... never heard of him before, just know that he's Tapia's sub... which can't be a good thing, since Tapia failed at Santos)
Palmeiras made decent signings in Edmundo and Paulo Baier, though maybe their team is a bit old... They do have a good team, and they are leading the regional championship winning all their matches so far though.. and in Emerson Leao they have the best coach in Brazil
Internacional is decent, they probably should have been national champions last year. Rafael Sobis is awesome, and if they manage to keep him (Corinthians want him) they should be a major force, though they lack international experience
Goias had a great run in the league last year, but they couldn't keep their best players.. it'd be a surprise to see them doing well...
Paulista is very happy to be where they are... they're in the second division, and got their place through the cup... I can't see them getting many points
Sao Paulo is playing poorly at the moment... with Amoroso, Cicinho, Grafite all going to Europe, they are yet to find decent replacements, though young attacker Tiago seems to be very promising... also, with Lugano and Ceni, they aren't that bad in their defence too... their major loss though since the last year's competition was Emerson Leao...
I guess I didn't forget anyone...