The other factor is IBR. If you expect to be in a position to rapidly pay off the debt, then I guess 2.25+LIBOR is a good deal (esp. since the Fed plans to retain near-zero rates into 2014, and I believe LIBOR is influenced by the Fed rate?). But I'm not sure what I'll end up doing (professionally), and I don't have tremendous confidence in my potential to earn a high salary right away...so I'd like to have the option to control my repayment. Private loans (like Sallie Mae) cannot be consolidated under IBR, ICR, or any of the federal consolidation programs.
LIBOR stands for London InterBank Offered Rate
It is the rate at which (international) banks lend to each other.
It is not directly related to the fed rate (it has nothing to do with the Fed).
However, while the fed rate and LIBOR are independent if each other, they do impact one another, so a drastic change in one will cause a change in the other
It's hard to predict how long LIBOR will stay where it is if you consider the potential issues in Europe at the moment (please lets not get into a discussion on this)