In college, Trufant could use his ball-skills and aggression to handle bigger receivers. In the NFL, his assignments will be bigger, more powerful and have better ball-skills. If he doesn't get significantly stronger, he will never be able to counter those players in single coverage.
Trufant is valuable because of his coverage potential, but without a greater physical presence, that potential won't ever be reached.
While it is a less looked upon aspect of his game, his size could also negate his aggression against screens on the professional level as receivers tend to be better blockers and bigger. Even in college there were times when Trufant was simply pushed passed receivers or missed them in space because he came in too fast.
Trufant doesn't appear to have a huge amount to learn from better coaching. His footwork is already impressive and he reads the game well. Becoming a full-time professional athlete shouldn't cause a major improvement in his play, but it should help him develop physically.
Against Stanford, Trufant played free safety when the offense went to tight formations. He was caught out of position more than once and didn't look overly comfortable at the spot. Maybe if transitioned to the spot in a full-time role, he could excel there as he certainly has the skill-set, but it's unlikely he is moved away from cornerback in the NFL.
He also played inside as Washington's nickelback in college. With his agility and aggressive ball-skills, Trufant could easily become a full-time starter on the outside who moves inside with regularity a la Leon Hall or Lardarius Webb. Webb and Hall are different types of nickelbacks. Hall is better at covering possession receivers or tight ends, while Webb offers a physical run-stuffer and edge pass-rusher. Trufant is somewhere in between and would play the game in a similar style to William Gay of the Pittsburgh Steelers.
Trufant is the type of player that every NFL team would happily have on their roster. However, his value to different teams will range from very high to just a decent fit. He doesn't appear set to follow Richard Sherman, Brandon Browner, Darrelle Revis or Antonio Cromartie as almost exclusively man cover cornerbacks. Instead, he should find his home in a defense that will run multiple coverages to take advantage of his all-around skill-set. The Patriots definitely fit that mold.
His aggression attacking screens and the ball in the air is reminiscent of Cortland Finnegan, but his coverage ability and ball-skills are similar to that of Brent Grimes.