I hope you're not suggesting that they incorporate the FFXII battle system into FFVII. Because that would instantly mean that a remake would be awful. =/FF7 has a great script, with many interesting stories, but the graphics can be very annoying...for pc there are mods of course, but nothing compares to a PS3. But it's not only about the graphics, its about sound too: don't forget that ff7 used midi. As for the battle system, well, this one is more complicated...ff7 battle system is great, but i liked 12 better - i just don't know how diferent the game could be...
Anyway, if square-enix stayed with the inicial script and kept the same environment it could result in a great product, but i guess we'll just have to wait and see...