From the FDIC:
...JPMorgan Chase acquired the banking operations of Washington Mutual Bank in a transaction facilitated by the Federal Deposit Insurance Corporation. All depositors are fully protected and there will be no cost to the Deposit Insurance Fund.
"For all depositors and other customers of Washington Mutual Bank, this is simply a combination of two banks," said FDIC Chairman Sheila C. Bair. "For bank customers, it will be a seamless transition. There will be no interruption in services and bank customers should expect business as usual come Friday morning."