Could mean a little or a lot depending if the Saints hire from within.
With Brady having retired and the Bucs on the verge of losing a # of key players due to FA (likely a factor on Brady deciding now was the time to hang it up), the Saints (if Thomas is healthy; still need to draft a receiver early) could be in the driver's seat to win the division.
Right now, the Saints have 3 QBs under contract - Hill, Book and Bortles (signed to a futures contract), so they probably will sign one of Winston or Siemian, but maybe neither (if both get priced out of what the cap-strained Saints are able to pay).
Plenty of teams looking for a reliable back-up (if not a starter, like the Steelers).
With the 49ers likely parting ways with Jimmy G, Trevor would be the type of vet QB (with experience in a WC system) that they would be looking for to be in the same QB room as Lance (GB may be in a similar position if Rodgers ends up departing).
When Shanahan interviewed for the Broncos job (before getting hired by the 49ers), he told Elway that he liked Trevor - which is probably a major reason why Elway passed on Shanny (another major Elway blunder) since he was looking for a HC who would build up his 1st rnd QB.