The Darrelle Revis trade makes it more likely the Jets will trade down in the first round. Having both the 9th and the 13th pick in some ways would allow the Jets to have their cake and eat it too. They can take a top ranked player and still move down to accumulate extra selections as they try to rebuild their roster. So much depends on how things actually shake out, but if all things are equal, moving down from the 13th pick seems like a better move than moving down from the 9th pick.
What is the reasoning behind this? It's simple. The trade's failure to land anything tangible in 2013 aside from the 13th pick puts a tremendous amount of pressure on the pick to succeed. In many quarters, the player selected with be viewed as Revis' replacement and be compared directly with Revis. This isn't fair to that player. The odds of said player being as valuable as Revis are miniscule, but there are probably going to be unrealistic expectations coming from the press and various fans that will scrutinize the pick beyond reason.
If the Jets can trade down and get two picks, it spreads out the pressure a bit. You can start operating under the theory that two players at least in theory might be better for the rebuild than one legendary player. The pressure gets dispersed a bit in this scenario.
This player at 13 will be expected to contribute immediately as a rookie. You never want to expect big things from a rookie. It's more of a bonus if things do work out.
This is a largely academic exercise because everything depends on how the Draft plays out Thursday night. Scenarios may pop up that render this moot. There are situations that pop up where trading the 9th pick will be a better deal than the 13th pick. There might be a player at 13 who provides more value than what the team would get trading down. Ultimately, though, if all things are equal, moving down from 13 might be a better move than moving down from 9.