My impression is that this is yet another instance where you ought to do what works for you
. How does the studen loan make you feel? Is it a burden? Or is it just a minor nuisance? What's the balance? How quickly could you pay it off if you applied your energy to it?
If the loan is a burden, then follow sjpeer's advice, and take the Dave Ramsey approach. But if the loan doesn't worry you much, and you have confidence that you'll tackle it in due time, then by all means begin saving for retirement. An early start on retirement is huge
I'm willing to bet, though, that the best answer is to do a little of both.