This thread will be used for all of the 30th Survivor spoiling tidbits that surface before the show gets it's premiere.
While typically the content is usually of the cast reveal and minor possible leaks genre... Including but not limited to generalizations, stereotypical twitter conundrums and a possible CBS snafu. Keep in mind that while this thread starts looooong before the premiere, and will have to be bumped at some point post finale of SJDS, does leave it open to sources.

First and foremost... the premiere; Wednesday, February 24, 2015 | 90 Minute Premiere
If it suddenly changes dates and gets extended to 2 hours, note that it will most likely be 2 eps back-to-back versus an editing dreamland of character development.

We know that Nicaragua is being used again. The same locations blocked off for very similar looking beaches and confessional backgrounds.
From there we have these...

The following were graciously borrowed from the hard work of Fanofsandra at sucks. 174+ pages of typical sucks sludge condensed into 10 items. Somethings to nibble on.

* Possible heavy "shipwrecked" theme with the decor.
* The title of the season is the name of the twist, think "Redemption Island" or "One World".
* There are 18 new contestants. Possibly divided into three tribes.
* It's speculated that they are divided by social class or something similar.
* There are, so far, 7 contestants that have been spoiled:
1) Carolyn Rivera, 53, professional trainer from Tampa, FL
2) Joaquin Souberbielle, 27, marketing worker from New York City, NY
3) Lindsey Cascaddan, 24, hairdresser mom from Orange County area, FL
4) Max Dawson, 37, "Survivor professor" from Los Angeles, CA
5) Nina Poersch, 51, realtor from Los Angeles County area, CA
6) So Kim, 30, retail worker from NYC - she is speculated to be part of the female pair of loved ones that couldn't compete in Survivor: San Juan del Sur
7) Kelsey Moore, 24, Miss Texas USA, El Paso, TX

ALSO:
TDT has some pics of the prospectives.
SurvivorFever has a great compilation page going.