Volatility. The market makers are still picking off auto sells. As you can see, there is regular daily demand well above $260.
As for earnings tons of people would like them to miss earnings so they can buy below $240 and ride it up. That's why the stock won't really drop further. By 2011 when they have over $2 billion in cash that will be a futile wish.
That is going to be a big hot button issue going forward, physicians that own specialized treatment centers getting referrals from their friends/colleagues. One cancer center here in my area was gigantic and they went bankrupt once it was discovered they were over prescribing tests and treatments.