NIS america last night sent emails to the gaming press for their annual press event. The email included a photo of a Prinny about to blurt out the secret games, but he dosn't need to anyway, as the silhouettes behind the curtan are plainfully obvious the heroines from Ar tonelico 3, as well as others that could possibly be from NIS's Classic Dungeon. Now all we need to do is wait for July 15 for the official announcement.
Sources:
http://www.t-ono.net/Gaming-News/Ar-Tonelico-3-US-Release-Pending.html
http://scrawlfx.com/2010/05/ar-tonelico-3-localization-announcement-hits-july