The Jets have not had a guy capable of consistently getting to the quarterback since John Abraham. I do not for a second regret getting rid of Abraham. He was too injury prone and one dimensional for the Jets to meet his demands. The team also did better than all right by selecting Nick Mangold with the Draft pick acquired in trading Abraham to Atlanta.
The Jets still have had a lot of trouble generating pressure without blitzing in recent seasons (and many times even when blitzing). This team has a lot of talent on it. If the Jets are looking to upgrade the talent on the roster even further, one place they could do so is adding pass rushers. I have seen some say adding one should be a priority. I disagree. I think adding two pass rushers should be a priority. Having one quality pass rusher forces offenses to always account for that guy. Having two makes an offense pay for giving one guy too much attention. On top of this, diverting attention to a pair of good pass rushers makes blitzing, particularly zone blitzing as the Jets do frequently even more dangerous. The possibility of two rushers capable of winning one on one assignments on top of the potential for blitzers to come from any angle is enough to confuse protection schemes frequently. Look at what the Steelers have for James Harrison, Lamarr Woodley, and Dick LeBeau's attack system for reference.
Kiwanuka would definitely fit the bill as far as adding a pass rusher. I still want two pass rushers, but adding one puts a team halfway there. In his last full season, 2009, Kiwanuka amounted 26 quarterback pressures and 14 quarterback hits on top of his 3 sacks while rotating on New York's defensive line. I mentioned that he had a quiet 2009 in the first post of the segment, but that is only in terms of well-known stats. He had 4 sacks in the first 3 games of 2010 before suffering his injury.