The latest AARP bulletin has several articles on the subject. If you recall, the heads of the Big Three automakers went to the WH to make a similar appeal.
companies with large union work forces are stuck contractually. but unions are a small percentage of the US private labor pool, the rest of those companies are already making changes to their health plans on their own to share costs with the employee. they don't need an additional kick in the pants from a government tax to "help" them. they could however, benefit from a medical 401K program - to give their employees choices.