God Eater 2 Rage Burst is set to be an expansion of God Eater 2, which was released back in 2013 on the PSP and Vita. If this is anything like the expansion of the original (God Eater Burst) than it is going to feature new characters, monsters, etc.
Yusuke Tomizawa from Namco Bandai went on to say during the conference that being able to bring the series to PS4 will allow it to live on and they will be able to try new things with the franchise. This is the first God Eater title that will be released on something other than a handheld device.
We will have more details on this game as they emerge at the Tokyo Game Show.