Hospital Fears Health Care Reform

The issue of government lead medical insurance reform has hospital administrators shaking in their boots and I don't know why. What is the downside for hospitals? I mean, more insured patients should mean better cash flow, fewer write-offs, and therefore more stability for the hospitals? Is the fear based on price setting or something I am missing? What do the rest of you think? I happen to think the proposed reform is a good idea, as I have many friends and neighbors suffering now because they are un or under insured.