It is confirmed that the Last Remnant is NOT a KH game, rather a completely new game. From Game*Spark:
(Sorry, this is directly translated from the site so it is a little off.)
New work RPG of [sukuuea] [enitsukusu] became clear.As for the title where special edition is united with Game InformerThe Last Remnant。This in the past [sukuuea] [enitsukusu] trade mark with as in the word which has been registered, that coming here, reached to the announcement of new work title.Spring 2008In sale schedule, the platform has been decided the “next generation console” only.KotakuSo the multi-platform development with PS3 and Xbox360 is expected from there.
The license was acquired in the pastUnreal Engine3With this title the pattern which is used.Is concerning contents, but as understood from the picture, the character two, the both seem like the prayer character.In addition to thatMitra, Yama, Qsiti and SovanniWith four races who are said are verified.ThisDividing into two armies, the system which fights is expected from the picture which is thought as the game picture.It is RPG perhaps, but it becomes something which includes the strategy element.Don't you think? to be prompt with [sukuuea] [enitsukusupatei] 2007 of opening, there is also a possibility where there is announcement concerning this title.
(Sorry, this is directly translated from the site so it is a little off.)