At 7-5, the Bucs would be able to put a stranglehold on the division with a win (fun game: see how many articles use that phrase in the leadup to this game -- the usage of English in sports media is atrocious ... and I am a hypocrite). If the Bucs win, their record would stand at 8-4, while the Saints would fall to 5-7. In addition to having a conventional three-game lead over the Saints, the Bucs would hold the first tie-breaker, head-to-head record. Ostensibly, the Bucs would have a four-game lead in the division with four games remaining; the only way the Saints could win the NFC South would be by out-winning the Bucs. In other words, the Saints would have to win out, while the Bucs would have to lose four straight.
But, hey, at least the Saints are only a game out of the wildcard standings (top-6 go). They must pass slumping Detroit to move up.
Bless this (parity) mess
Also, should the Saints win Sunday, and win by nine-plus points (they are favored by three -- WHY???), they would be even in point-differential. But now that I've mentioned all this stuff, none of it's probably going to happen.
Enjoy your division title, Falcons.