Besides Active Time Battle system, only the cinematic detail is new :( Still is a new Final Fantasy adventure.
The battle system has been changed, and I suspected it would make the game too easy... it's not real time, but active time where the characters can only move so fast relative to each other. I felt that if you could button-mash your attack sequences in, winning battles should be easy. However, I have faced several very challenging boss-battles and many tough regular enemies. This game, you can see the enemies and try to run around them and avoid battling them, but sometimes they catch you. Lastly, there are changes to the battle parties... no more hot-swapping members in and out of battle, but you use "battle paradigms" to coordinate your parties strategies in real time (balanced, offensive, defensive, physical, magic, healing, etc). You must be more aware of each character's development as a battle begins, to know if there are tasks each member is well suited for. Very cool, changes strategic approach to FF battles! I like it.
Graphics and video? Esthetically beautiful and fantastic! I wonder if anyone involved in the production of FF XIII was involved with the movie Avatar... okay maybe that's silly, but that's how impressed I am with the video quality of FF XIII!
Gameplay: As a kid playing the new FF on the SNES, possibly on the original Nintendo too, I guess you could assume I enjoyed it then if so many years later I am eager enough to pre-order FF XIII for release day!
Pre-teens may enjoy this if they like this kind of story (kids fighting monsters and demons in a fantasy world). This may also become a collector's item or otherwise appreciate in value, much like FF VII for PS1 currently is. Go for it!