I'm really hoping they'll preserve the open world-map exploration of the original. Maybe they can re-scale everything to more realistic proportions - imagine walking around a life-size Midgar and viewing it from ground level.

There are only two slight problems with FFVII's world map from this point of view, though: (1) the cableway from Corel to the Gold Saucer, and (2) the rope bridges in the mountains around Wutai. If you imagine that the world map is drawn to scale, then those structures would each be hundreds of kilometres long in real life, which is manifestly absurd. There'll need to be some re-scaling in order for things like that to make sense.