I'm not really a big FF fan nor have I played FFVII but this is still major news. This is an announcement designed to make waves at E3.
They didn't give any details but it's fun to speculate. Will the story and characters be the same or changed up so that fans of the original will get new surprises? Turn based combat has evolved since the original game so how will this remake take that into account? When the original Resident Evil was remade it played pretty close to the original even though the series had evolved past that point. So there's an argument to be made that the game could stick close to the original play style.