Going by what this dude at SA wrote about the game, who has clocked about 20 hours, the game is the anti-FF13: there's towns, there's an actual semblance of level design, there's customization up the wazoo, the new dialogue system adds to the game (but not in the way it would in say, a Bioware game or anything), and sometimes the line is blurred between sidequest and plot progression.
He also says that anyone who enjoyed FFXIII's world, but didn't like how it was so underdeveloped or let you have a feel for it, will really enjoy this game as it fleshes out FFXIII in general.
He said he spent four hours in the first area just questing and fucking around and that by hour 10 he was positively overwhelmed with all there is to do.
Awesome.