Tales of Xillia's official site was updated today with an announcement video, saying that the game's next trailer will be released online this July 8.
Looking at the video, the trailer will most probably show some of the game's anime scenes.
The upcoming trailer is labeled the third one. Apparently, the Scenario/Story and the System trailers from Tales of Festival are considered collectively as the "second" ones.
On a sidenote, the official site was also updated with the info on the Random Treasure and the Shop Build game features. Tales of Xillia's Next Trailer Scheduled On July 8