Transferring student loan debt to credit cards?

I have a mountain of student loan debt. Most of it is locked up at about 3%, consolidated at the perfect alignment of the stars and planets a few years ago. But about 16k is through an evil private lender whose rates keep increasing along with the Fed. They're now at about 8.75%.

I receive many great credit card offers, most of which only offer a low rate for a year or so. But I also have one from Discover, offering a fixed 3.99% through something like 2010. The minimum payment will likely be more than the monthly loan payment, yes, but is there any reason why I wouldn't do this? What are the credit ramifications of doing this--any experience, anyone?