Deadline.com is reporting that CBS has cut this season's episode order for sitcom from 18 to 13 (which added to 2 left over episodes from last season would make 15 episodes total for this season).
Based on its ratings alone, as recently as last week, I judged the show a very good bet for another season's renewal. Even with the episode order cut, I wouldn't count the show out just yet, but I'll make it a toss up for renewal or cancellation in the next Renew / Cancel Index post tomorrow.
CBS may choose the expand their sitcom hours in next season's schedule. If they do that, I'd expect them to keep Rules around.