I suspect the cartoony look will go, and some of the charm with it. It's risky, but also pretty exciting. This is FF7 for a new generation of gamers and elements are bound to be different.
My favourite is FF6 and I wouldn't like a current remake of that, but FF7 should lend itself better to a revamp.
An FFVI remake in the style of FFIV DS on the 3DS would be great. Give it the same brutal difficulty as that and it would be amazing.