http://forum.square-enix.com/ffxiv/t...=1#post1913954

the post is in french but the quote from famitsu's interview is in english (Reinheart's translation)

Also, Elmoria confirmed that IF they drop PS3 one day, the notification will be made soon enough to allow the transition to PS4 with no problem, and it would be made ONLY IF enough players had dropped PS3 for the PS4 in the first place. She also said that saying anything like "PS3 will be dropped" would be pure speculation and thus has no real truth for the moment.