It is a SATA-III drive. SATA is backwards compatible, so it should work, but you won't be able to get the full theoretical speed out of this drive, as the MP's SATA interfaces are slower.
A long zip-tie loop works fine as well in the HD bays, to serve as a harness to hold the SSD in place.
MP's only support max SATA II speeds default, so unless you're getting a good deal on the Vertex 3 you're not getting any of the benefits of the SATA III rev.