ESPN's Field Yates has reported that the compensation going to Detroit is a future seventh round draft choice.
Williams adds some additional depth to the ends of the Patriots offensive line, and could make players such as Cameron Fleming or Marcus Cannon more expendable. Considering his experience at tight end during his time at Alabama, he could also make a player such as Michael Hoomanawanui expendable. Hoomanwanui has continued to struggle as a blocker in the preseason, and Williams, should he make the roster, could be an upgrade to Hoomanwanui's blocking with James Develin and Scott Chandler providing more of a pass catching presence.
In unrelated news, ESPN's Adam Schefter is reporting that the Denver Broncos have agreed to terms with free agent guard Evan Mathis.