When Regehr's contract is up, he's not coming back. The same might be said about Stoll, and Nolan. But Williams will probably get another contract. The team needs the extra money to sign Muzzin, Martinez, Toffoli, and Pearson.
If next year Kings do well, really really well and do what they do best (aka 3 in 4
) Stoll will be back, probably with pay cut and a bit lesser role, and you can bet your house on it .
He will have 33y, not too old for one more tour with Kings, and contrary to some of posters here Kings will have more than enough cap room for both Williams and Stoll (there is nothing that can stop Kings giving Williams and/or Stoll contract that is similar to one Gaborik received, longer term and lesser cap hit, with no risk of any kind of cap penalty) without compromising resigning of Pearson, Toffoli, Martinez, Muzzin or Kopitar(assuming cap keeps growing to ~73-74M in '15/'16 and ~75-76M '16/'17).
Regher is only player that is unlikely to resign with Kings after his contract runs out.