This sounds about right. The Jets have often been connected to Mark Barron in the first round, but after passing on him they can find value here in the second round with Smith.
SB Nation's Gang Green Nation explains the pick:
The Jets addressed one huge need in the first round by taking Melvin Ingram. I could see a scenario where they double dip at the outside linebacker position, but it probably would not be in the second round if the Draft plays out this way. Regarding their other needs, reports indicate they are intent on signing a cheap veteran receiver after the Draft. For reasons unknown to anybody, they seem content with Wayne Hunter battling Vladimir Ducasse for the right tackle spot. That leaves us with safety.
Eric Smith was one of the worst starting safeties in the NFL in 2011. Despite the signing of LaRon Landry, Smith is currently slated to start again. We'll replace him with another Smith. Landry is an in-the-box type of safety. Harrison Smith has the skillset to play centerfield in this defense. Adding Ingram and Smith in the first two rounds takes a defense that was already one of the best in the league and makes it potentially dominant.
For more analysis of the pick, visit Mocking The Draft.