FFXII was leaked a few weeks ago, and like everything leaked I just had to have it but enough about that (I won't tell you where I got it) - it gives me a unique perspective to view this topic though as I have played the game.
Firstly: The battle system is quite different from any of the rest - think of it this way, you know how Kingdom Hearts has computer controlled characters and you engage in battles without any loading? This is a bit like that. Your entire party and your party leader directly controlled by you can be controlled with things called Gambits, these are things which dictate how they behave as in "Foe: Any - Attack" As soon as you approach an enemy your entire party will target that monster and fight it.
You can controll them all manually as well and sometimes you will have to especially in boss battles - the whole battle experience is quite a bit semi automatic because you can overrule the gamebits manually at any time - at first everyone says that this makes the game easy - Dead wrong. Anyone who plays FFXII will learn quite fast that this game is very difficult, I have been killed about ten times as you can end up with about 10 enemies attacking your party of three in some points which means only one thing "RUN for it"
Secondly: The story, WOW what a story, it opens up with an amazingly well rendered FMV sequence and is quite epic. Basically some countries or lands are at war and Dalmasca is being invaded (thats your country) by a bigger more powerful group. Shortly after the intro sequence you begin your training and more stuff happens, I don't want to ruin the story anyways, play the gam e yourselves.
Thirdly: Music - Also wow, there is a new composer but hot damn i'd say he's actually better than the original some of the time, three words: Best Music Ever - I actually look forward to the boss battles because I love the boss battle music. The replacement has done a great job with the music as everything seems to feel just right to me.
Finally: Graphics, already talked about the epic fmv's, theres plenty of them - better than FFX's in quality. Graphics are great and square have pushed every ouce of power out of the PS2 by the looks of it... everything has been revamped from player models to levels to even the Menu. The menu graphics look quite cool.
YouTube - FFXII Gameplay <-- something I made earlier showing off the battle system a little. Game comes out next year officially for me but at the end of this month for you american's. I shall have to import it.