According to Siliconera's interview and article, sale it was mainly due to the fans that Tales of Graces F is getting a localization. Also, click it seems the platform for the NA release is still unclear.
During the Namco Bandai press event, Carlson Choi, Vice President of Marketing, mentioned that they have received over 50,000 request for Tales localizations. They made a puzzle which they estimated people would solve in 40 hours... but the fans managed to solve it after a measly nine and a half hours.
In Siliconera's interview with Makoto Iwai, the Bandai Label President, the existing fanbase for Tales is quite strong. Simply put, all the commotion has become too big to ignore, so they will now prompt to try and embrace the community as the company's challenge.
Upon asking to clarify if Tales of Graces F will be localized for the PS3 or the Wii, Iwai replied promptly that they're still working on it and that they will just make an announcement later.