Without Manu and Oberto on the Argentina team, there was no way anybody was going to beat the USA team this year. Brazil has a couple of very good players, but most of their guys simply lack the talent to compete with USA.
Alll this year's team is doing is learning to play as a team and get used to FIBA and the way games are called. But next year, they will face a vastly more difficult challenge against teams with enough talent that their experience with FIBA will really matter. Of course, they've not played against Kobe yet.