Bill Clinton's labor secretary, Robert Reich, is suggesting that the Obama administration "put BP under temporary receivership." Mr. Reich: "If the government can take over giant global insurer AIG and the auto giant General Motors and replace their CEOs, in order to keep them financially solvent, it should be able to put BP's North American operations into temporary receivership in order to stop one of the worst environmental disasters in U.S. history." Link via Mike Allen's Politico Playbook.
One of the bad things about the federal seizures of private property during the financial crisis is that it establishes a precedent for subsequent actions along the same lines. I don't think there's any way this is going to happen, though, because it's too politically risky for President Obama. Right now, he can still blame BP for the leak. If the federal government takes over BP, then the failure to plug the leak becomes President Obama's fault even more inarguably than it is now.
Mr. Reich's article doesn't really deal with what legal or constitutional authority the federal government would use to justify the seizure.