Cass Sunstein
Van Jones (he has said this several times)
Carol Browner
John Holdren
—don't know the fifth person
We'll see if that is correct. I haven't watched yesterday's show yet.
There's a spreadsheet on Google listing his czars.
http://spreadsheets.google.com/ccc?key=0ApAPLR-rjqg3dFU0cmVvT2VOOVNnZnJETEJCbkd0THc&hl=en
Ezekiel Emanuel was the fifth guy.