Afflalo isn't the same player he was earlier in his career, and definitely won't fix all the problems the Kings have on defense, but he's still a big upgrade at the Shooting Guard position. He's a career 38.5% shooter from three, and even last year in what was considered a down year for him in New York, he still managed to shoot 38.2% from long range.
The contract is very reasonable as well for someone who should immediately be slotted as Sacramento's starting shooting guard, and the two year length means the Kings don't have much risk should Affalo not pan out. Afflalo could also pick up some of the offensive slack should the Kings end up trading Rudy Gay.
It remains to be seen whether the Kings will still pursue Dion Waiters or Courtney Lee now that they've acquired Afflalo. Ryan Anderson is still in play and will likely be deciding on his future soon as he's already taken all of his meetings.