Yeah it's basically all-stars with a twist. I thought it would be neat to have all 20 winners on the show but that's not possible.
Here's a blurb on the potential cast:
"If casting rumors are correct, this will be the first time that some contestants are able to play the game for a third time. Among the possible “threepeats” are Jon Dalton (AKA “Johnny Fairplay”), who is best known for lying about the death of his grandmother while competing on Survivor: Pearl Islands and later being the first voted off of Survivor: Fans vs. Favorites, and Stephenie Lagrossa, the last remaining member of her Ulong Tribe on Survivor: Palau and the runner-up of Survivor: Guatemala.
Past contestant Coby Archa claims that at least 35 former contestants were contacted about possibly appearing on the show, and were interviewed in Los Angeles at the beginning of the month. Of those 35, apparently 10 had already appeared on the show twice.
Archa has also revealed that Natalie Bolton (Survivor: Fans vs. Favorites), Ace Gordon (Survivor: Gabon), Shane Powers (Survivor: Exile Island), Amanda Kimmel (Survivor: China/Fans vs. Favorites), and Parvati Shallow (Survivor: Cook Islands/Fans vs. Favorites) were also asked to participate.
Host Jeff Probst had previously revealed in his Entertainment Weekly blog that if there was ever another All-Stars season, Survivor: Tocantins contestants Benjamin “Coach” Wade and Tyson Apostol would be shoo-ins. Thus, it is likely that at least one of them, probably Coach, will be appearing on the show. Probst also expressed his interest in seeing Survivor: Tocantins winner and fan favorite J.T. Thomas Jr. return."