The old main scenario does suck. The GC quests have me liking the imperials, at least. Nael (the white guy) is a decently good crazy villain but I'm pretty sure we're going to kill him in 1.23. That will leave us with Gaius (darth vader) who could be pretty cool if he's given more screen time.

They also introduced the sultana of Ul'dah in one of the Immortal Flames quests. The job quests have a lot of good characters too.

If they add a bunch of main scenario quests (like have the current level 46 one happen at 25, and then have a lot of new ones all the way up to cap) then they'll have plenty of time to flesh out characters.