Right now, Jerrell Jernigan's role will be as a punt returner, a big area of need, and perhaps as a slot receiver if Steve Smith leaves via free agency or returns slowly from injury.
Jernigan is a value pick, and his best football is ahead of him. He's extremely quick but also a tough customer. Jernigan must work on his ball security, though, and he'll have a handful of veterans to beat out for a regular spot on offense.
For now, keep him in the back of your mind and monitor the Giants' transactions through the offseason to see where he fits in on the depth chart.