The Tales of Zestiria site updated with an onsite countdown to the game releasing in a week as well as dates for the announced DLC.
Evangelion Costume: January 22, 463 yen
iDOLM@STER Costume: January 22, 278 yen
School Costume: January 29, 278 yen
Blue Exorcist Costume: January 29, 463 yen
BASARA 4 Attachment: 185 yen
Tales of Costume: February 5, 278 yen
Swimsuit Costume: January 29, 278 yen
Famitsu will also have a code for a Mecha Asbel attachment in the issue releasing next week.
And one of the character cameos has been revealed to be Jade Curtiss from Tales of the Abyss.
Series producer Hideo Baba confirmed on Twitter earlier that playing Tales of Zestiria on a PlayStation 3 with save data from other Tales games will net you some bonuses. Some of these will look familiar if you played Tales of Xillia 2 with save data from other games too.
Tales of Symphonia Unisonant Pack will require save data from both games in order to unlock both bonuses. Otherwise, you only get the one from your save data's respective game. (Also gonna assume Xillia will need a Jude Side save file for Jude and a Milla Side save file for Milla, since that was the requirement for Xillia 2's unlocks of both, but I can't say that for sure since they haven't said that yet.)
Tales of Vesperia (Yuri Attachment)
Tales of Graces f (Sophie Attachment)
Tales of Xillia (Jude and Milla Attachments)
Tales of Xillia 2 (Ludger Attachment)
Tales of Symphonia (Lloyd Attachment)
Tales of Symphonia: Knight of Ratatosk (Marta Attachment)
Note that these conditions are for the Japanese version. For other releases outside of Japan, fans will at least be able to have Graces f, Xillia, Xillia 2, Symphonia, and Dawn of the New World, so I'd imagine in the localized release they'll change the Vesperia one to work with one of the other games like they did in Xillia 2 and Symphonia Chronicles.