The counterparty was the troubled bond insurer ACA Financial Guaranty, which Moody's cut dramatically from A to triple-C one day in December.

FORBES: You Should Worry About Ambac

That "hands across Wall Street" effort seems unlikely now, though banks are meeting with individual bond insurers, including Ambac and Financial Guaranty (FGIC), two of the companies that are the targets of the Buffett offer.

FORBES: Buffett To The Rescue!