Looks like the authorities are keeping the green 1-94W form a while longer before doing away with it.
From FAQ’s
Q: If a VWP traveler has received ESTA™ approval, does he or she also need to fill out an I-94W?
A: ESTA will allow DHS to eventually eliminate the requirement that VWP travelers complete a paper Form I-94W prior to being admitted to the United States. While DHS continues to work together with the airlines to fully automate the I-94W process, all VWP travelers applying for admission at a U.S. port of entry, including VWP travelers who have obtained travel authorization via ESTA, must present a completed Form I-94W to U.S. Customs and Border Protection.