In news that is sure to have Washingtonians clutching their BlackBerrys just a little tighter, the Supreme Court is refusing to grant a rehearing to BlackBerry’s Research in Motion (RIM) Ltd. regarding an on-going patent-infringment case. Cutting through the legalese, these simply means that BlackBerry users might be facing dark days down the road. Canada-based RIM has been embroiled in a legal battle with NTP Inc., a McLean-based patent-holding company that has the licenses for…