All I can say is that the way the game was sounding before E3 I wasn't sure if it will be good or not, after seeing the footage though I think the game will do very well, the combat system actually looks right by having bullet time effects to decide what spells and such to use and being able to switch characters is a big plus it strongly reminds me of the Star Ocean games with modern twists and I always liked that combat system. Tifa looks good as well looks really well designed and keeps the original look but more fleshed out and detailed. Actually will laugh if people are moaning bout her tits size lol they look fine to me.
If the game plans to be more centered around Midgar I'd say they're likely to include the other sectors both upper and lower as the one thing about Midgar is you see very little of it in the original game literally a bit of sector 1's upper half and parts of 5/6 and 7, I'd also say that they might make Biggs Wedge and Jessie playable or support characters if they expand the story out significantly as they're both part of the original game but we all know they don't survive past sector 7's fall.
I wouldn't be suprised the game is so good is because they realised when they were developing it that the intial iteration was going to be crap and didnt want a repeat of FFXIV 1.0. Definately gonna buy this when it comes out.