The impact to yoru score should be minimal. There will be a new account, which will hurt your Average age of accounts. This will lower your score, but it will improve in time.
The advanatge is, since you only have one bill to pay, so you are less likely to be late, and if you are late, only one account is late. WIthout consolidation, its easier to forget a payment, or its possible to be late on multiple accounts.
I wouldn't worry about the impact on your FICO score. My bigger concern would be if consoliation is in your best interest. A while ago, consolidating loans would lock in your interest rates, but since loans have a fixed interest rate, that benefit is gone, so consolidtion still makes sense for some people, but not for everybody.
