If the Jets can manage to beat either PIT or CIN...
Their odds of making the playoffs are a lot greater. Assuming that NE (unfortunately), Balt, Houston, and Denver will win their respective divisions, there aren't a whole lot of other AFC teams that look like locks to make the playoffs- 2 of the best of the rest of the bunch are the Steelers and Bengals. The Jets happen to play the AFC North- if they somehow win both or one of those games, they will be in a favorable spot when it comes to seeding and tiebreakers.
Obviously, this is only focusing on intangible factors. Regarding the QB situation, it's likely that Sanchez will be the opening starter, much to the dismay of me and plenty of others. However, he is on a much shorter leash this year because of how awful he played last year and the fact that the Jets drafted a rookie in Round 2 this year. Nearly everyone is looking at this as a rebuilding year for the team and regardless of what Sanchez says about how happy he is to be here and how he's going to start throwing the ball away more or he's "confident he'll be the starter for x many years", the fans aren't buying him and are eager to see what Geno can bring to the table.
Last year was an anomaly for rookie QB's w/ 3 legitimate immediate impact players. However, if Geno Smith makes mistakes this year, the fans won't immediately want him out of town since he's a rookie- Sanchez played like a rookie in his 4th season. If Smith can play at the level of Nick Foles, I could see the Jets contending for the #6 seed in a weak AFC. Foles put up some big numbers last year but the Eagles' defense was terrible- I see some potential for the Jets' defense to be strong so even if Sanchez wets the bed again this year, Geno Smith may not have to play like Peyton Manning or Aaron Rodgers in order for the Jets to become a decent team again.