FF7 was a great game for its time, and helped to further popularize the genre. The problem with this remake is that it will accentuate all the flaws in the writing. We no longer live in the era of text dialogue; there will be voice-acting. The voices themselves may be criticized, and hearing them utter certain lines from the original will be cringe-worthy. When you have to read something, you may interpret and hear it in your mind differently than when someone else says it. It also doesn't help that Japanese stories for this demographic tend to be quite dramatic and rely on monologues to begin with. I feel this game will open the eyes of many longtime fans, but not for the better, unfortunately. =P
But that's as far as story goes. The gameplay of FF7 is good, but a bit outdated--specifically, the frequent random battle encounters. They need to fix that or give us some repellent options (e.g. Pokemon repels). The battle system itself needs some updates to modernize it, keep it fresh, and make it more dynamic. Finally, the scope of the game was already insane as it was, so translating that into the current or future generation of video games will be challenging. I recall there being many sidequests and mini-games to do too. It provided a lot of freedom in an era where this was pretty unheard of, but we're used to even more freedom now (and even more so in the future from now), so I don't know if they will expand the over-world or if it's hard to cope with what they already need to work with.
All in all, I can't wait for this game. That said, it probably won't come out until I'm 40, so whatever...