I don't think Spike is too concerned with keeping the storylines a secret, it's just a cheesey thing to do to your viewer.The producers are obviously fans of the genre - they use music from the Mole and they offer up lots of homages to other shows that reality junkies will enjoy but won't distract the casual viewer too. I think that's great and really clever!
Who knows - maybe they release this photo and do the previews early as a hats off to the spoilers out there.
TVGuide always has the episode titles early (due to pub. deadlines), and the previews are always what vid cap spoilers use to analyze.
I also thought that it would be kind of funny if that picture of the final three isn't the final three at all and there's actually like three more contestants just out of the picture!
All of those things would be great inside jokes to the people watching the show. It just is so silly when they show these dramatic, tense moments at the elimination ceremony to build this mock tension and then the very first commercial is a preview of next week's episode with the chick marked for eviction at the center of the clip.