It's not inconceivable that the credit crises can lead to wholesale failures. Just look at the savings and loan crisis of the 1980s. But in this current crisis, Fortune notes that we're not likely to experience any major failures. That's in part due to the aggressive capital raising moves being effected at Citigroup, Merrill Lynch and other banks. Recently, there has been only one bank shut down by the FDIC: Internet start-up NetBank, which filed for other reasons. But while no outright failures are expected, we could see some banks merged into a new existence. No one would be surprised if Bear Stearns were bought and merged into another company. Same goes for Wachovia. 

For more:
- here's the Fortune article