Apparently, Bodog.com (a web-based gambling site) noticed a conspicuous series of $100 bets (their max) on a particular contestant. As a result, they've cancelled any further wagers on Survivor.
The article I found on Yahoo was nice enough to warn before spoiling with who the contestant is, so I don't know (although I've bookmarked it). If anyone wants to be spoiled, you can see it in the Yahoo entertainment news (I'm pretty sure).
Interesting... remember way back in Survivor 1 where someone was intercepting the satellite feed, and people were analyzing episodes frame by frame looking for clues?
Thought I'd share...