Just had a look at the countries already qualified for the Olympics and the teams competing at the FIBA Omympic qualifiers. We have:
USA
Spain
Argentina
Brazil
France
Australia
China
UK
Tunisia
Then through the qualifying I think Lithuania, Greeca and Russia will get throughg. Potentially NZ has a the slightest hope, they should make it to the semis (they have possibly the greatest draw ever) but then will have to knock off either Lithuania in their semi, or the loser of Greece and Russia.
So after all that, I would pick only the US or Spain chances for gold, with maybe Argentina or France as long shots (france is loaded with NBA players, but traditionally can't manage to do anything as a team).
I think the Olympics for Basketball is kinda like the world cup in soccer where it only takes one slip up and your out or one lucky/great game and you can go a long way. And because of this any team can beat anyone? except maybe for Spain and the USA. So I think Autralia should fit in with France, Argentina, Lithuania, Greece, and Russia for a spot between 2-8. And I definitly think that a bronze or a fouth place is possible given a good run, the team geling, and a lot of luck