Have you already provided proof of income to WAMU? If so, they have probably already analyzed your POI and moved to the next stage of the refinance process. The real question is, can you still afford your mortgage payments with the loss of employment? If so, you should be okay in moving forward with the refinance. If not, I would recommend talking to WAMU about your situation to see if they offer any kind of homeowner assistance. It's possible they have a program that could work for you and your current mortgage (i.e., you may not even have to refinance).

If you have not gotten to the point of providing proof of income to WAMU, you must disclose your recent job loss. And keep in mind that lenders don't normally count unemployment benefits as income. Being open and honest with your lender often is the best way to stay afloat during these tough times. They don't want to see you default any more than you do. Hope this helps.