WaMu is mine too Timothy.
I had a Providian card before WaMu bought them. had $3,200 cl on it. After the buyout, WaMu decreased cl to $1,320. Almost closed the acct. because of that. Glad I didn't.
To original poster: I too got a pre-approval letter in early October. I applied over the phone, was told to expect their reply in 30 days. Uggghhh.
3 weeks later I received a new WaMu Platinum Visa with $6,500 cl. By far my highest cl card.
If you apply, keep low balances on it, and pay WELL before the due date. They will treat you well.
Good luck and do please keep us informed as to how it went.