Loan services providers can offer you substantial discounts if you consolidate your student loans with them, usually up to 25%. The consolidated loan interest rate cannot exceed 8.25%. However, take note that loans can no longer be consolidated while you're still in school.
If you have the option of choosing your own loan services provider, especially one for your student loans, don't forget to shop around. Some companies offer nice incentives to work with them, including rate reductions and rebates after on-time payments for a few years or so.