LAST EDITED ON 02-12-12 AT 11:56 PM (EST)
Yeah, Bobby Jon and Stephenie were dug out by spoilers a month in advance, and CBS promo'ed that there would be returnees for Guatemala but not who.
This time around, there's been bupkes in terms of scuttlebutt about any returnees and we've already figured out that certain contestants have lasted until the third or fourth episodes through vidcap analysis, but there's still nothing whatsoever about returnees. I think it's safe for you to start watching this season through to the finale.
ETA: For what it's worth, there are no boot lists or sourced spoilers revealing who might be making it past the merge - through vidcap analysis, we've speculated on the identity of one (1) contestant who may be there after the merge. Other than that, it's been a blissfully nice lead-in to this season with renewed interest in analyzing the numerous promos with old-fashioned pure spoiling through vidcaps.