I too would be disappointed if Costco drops Amex. I love my Amex and will NOT sign up for a Discover if Costco chooses Discover. I have 3 Visa and 2 Amex. I don't want to sign up for another credit card. Though I do spend a lot at Costco. I do most of my grocer shopping there.

I know it's a hassle, but there's a workaround if you want to pay for your Costco purchases with Amex. Just go to Costco.com and buy the Cash Card. Heck, you can use whatever card you want. Their website does accept all card types. Just a thought in case if anyone still wants to use their Amex and shops at Costco.