The vast majority of people are going to take a 6.8% Stafford loan and then a 7.9% grad plus on top of it. Some people are going to try and get creative and take private loans from banks. I don't think you'll see any real difference in the terms up front, but when you need flexibility at the end of the loan I sure hope they have all the protections the federal loans have. Last of all, some people are going to trade a tiny amount of interest on a private loan for having their parents co-sign their loans. The only idea that is worse would be seeking out a variable rate.
There's this strange idea that pervades this forum that 6.8% is an exorbitant amount of interest. It is not historically and its certainly not considering that we have no job, no income, no history and no assets. Minimize what you borrow, live frugally, and I'll stop preaching now.