If it's any other MacBook Pro with a Core 2 Duo other than the ones just released, then it's SATA II.
There is no such thing as SATA III right now.
To say that SSDs have no relation to SATA is ridiculous. SSD is a type of storage medium. SATA is a type of data bus connection. SATA does not denote whether the storage medium connected to it is using a spinning platter, flash-based storage, or calligraphy on papyrus -- it is simply a connection type. Every storage medium needs a data bus connection in order for the computer to communicate with it. Most SSD drives today have SATA connections. The SSDs used in Mac laptops (with the exception of the MacBook Air, which I believe uses an older IDE bus instead of SATA) use SATA connections.