Medical Device Safety Act of 2008 - Amends the Federal Food, Drug, and Cosmetic Act to provide that provisions preempting state and local requirements for medical devices intended for human use shall not be construed to modify or otherwise affect any action for damages or the liability of any person under state law. Makes this Act effective as if it were included in the Medical Device Amendments of 1976 and applicable to any civil action pending or filed on or after the date of enactment of this Act.