Russell now has a hidden idol again, but the Heroes should also have one in circulation, somewhere. Although since they haven't won any rewards since Tom used his, they won't have received any clues, and probably aren't bright enough to know to look for one.

    About the remaining idols to be found, SurvivorsUnite says there are four hidden idols found during the game, and all are played to take a player out.  survivrcuz begs to (slightly) differ, stating "more than 4 idols will be played and only one by the heroes the rest all villains, each time one is used it goes back in to play."
    Time will tell who is more accurate, but presumably someone, or multiple someones, should be busy finding idols at this point. Doesn't sound like any more are played until the merged tribe phase, however.