Either Bob Singer or Jim Michaels said at a Con that the CW marketing guys keep stuffing up the show by putting stuff into trailers and promos that they'd all been keeping quiet. I think they do manage to put their feet down occasionally - like keeping Matt Cohen's reappearance out of view before that recent episode, but most of the time they can't control what the network sees fit to release. I refuse to watch trailers now because they are either too revealing or just plain misleading.