Excerpt: As the head of Medicare and Medicaid, Mark McClellan ... was to rule [today] on one of the most heavily lobbied issues of the past year: whether to lift an 18-month moratorium on creating new physician-owned specialty hospitals. It's all very technical and bureaucratic, to be sure. But in deciding the issue, McClellan is being asked to choose between two competing and fundamentally irreconcilable models for the U.S. health care system.