I could swear I said this already...maybe I put it in the wrong topic, or something? Oh well:
I don't think VII's combat was "the weakest in the series." It's actually one of my favorite battle systems. True, at a certain point, it becomes completely broken in your favor, but as was said previously, that's more of a problem with implementation. Besides, I personally prefer it to the opposite extreme. Having to stop & level grind at every turn & get stuck at every boss just ruins the game's flow.
I definitely would not want it to have anything like XII's or X's.
XII's had promise, but the Gambit/AI thing needs some serious work. Also, they need to throw out the MMO aspect & make it more like action RPs with multiple characters. Both of those I think are a ways off, but KH 358/2 Days was a decent step towards the latter.
By contrast, I really liked X's system. So far, it's the only game in the series that borrows from FFT & doesn't make me completely sick when it does so. The thing is, I just don't think it works in this particular situation. "Let's completely revamp VII! New graphics, new content, the works!" "Alright! What about the battle system?" "Modified turn-based!" "...Really?"