I was at the Chase (née Washington Mutual) this morning.  Much to my interest, I got this message –> directing me to chase.com/cawarrants.

If you go to that link, you’ll see that Chase seems to be indicating that they will be accepting the IOUs for their current customers:

Can customers deposit or cash these warrants?

Certainly! Chase will honor the California registered warrants for our personal, small business, and commercial customers (with the exception of financial institutions) similarly to a check not drawn on our bank:

Other banks have begun to indicate that they may not be as eager to accept the registered warrants, but most banks will be accepting them until Friday at least.  After Friday, all bets are off.’

UPDATE: The subject just came up in Fiona Ma’s webcast. She believes that banks will stop accepting them after tomorrow, and that people will not be able to receive payment for services provided to the state. This is a problem.