I'm tremendously impressed so far. I first played last weekend and I was itching to get back into it all week, which isn't something too many MMOs manage (WoW, City of Heroes, and EVE are the only ones I can call to mind that have really done that). It seems well-balanced and well-paced, the world is as detailed and gorgeous as you'd demand from an FF, the music is unimpeachable, and the gameplay has taken what works from other MMOs like WoW and polished it up.

This may be the first MMO since WoW to actually improve on the formula. I'll have to play more before I can say that with certainty, but it's looking good, and I'm definitely going to be getting it.