From www.wdwinfo.com

Walt Disney World annual passholders to receive RFID passes
Mar 16, 2013

Walt Disney World annual passes will begin converting to new plastic passes encoded with an RFID (radio frequency identification) chip as of March 20. After this date, any new purchases or renewals of Annual Passes will automatically be given the RFID passes. Current annual passholders can convert their passes at The Odyssey Center in Epcot from March 20 through May 19, 2013. Guests will need their current annual pass, as well as a valid photo ID to make the conversion. This is a voluntary process and the current paper passes will still be accepted until they expire.

The new passes will look different than the current version; RFID passes will have a green background and have either an orange stripe across the bottom to designate free parking or a black stripe on the passes that don’t include free parking.

The RFID passes will allow guests to enter the theme parks through either the regular turnstiles or the new NextGen touch-to-enter turnstiles.