Things like Certificates of Deposit, savings accounts, money market accounts, checking accounts, etc., are generally FDIC insured, and as long as the Federal government doesn't collapse, are safe up to a total of $100,000.
Corporate bonds, on the other hand, are just loans to the company, on which they pay interest and on which there's a presumption that they're going to pay them back over time. Not being secured by FDIC or any other arm of the Federal government, they're generally as secure as the company that issues them.
As I understand things, WaMu corporate bonds are now worthless.