Well, if they go the grinderific model that was FFXI (where you not only have to level your toon once, but multiple times not to mention the horror that was crafting) I don't see this taking off. Grind crazy games like L2 and whatnot do well over the Pacific but not so much here. Also, it'd be nice to have more variation in mobs, at level 5 you're fighting rabbits, at level 55 you're fighting rabits, no change in powers (other than they hit harder), heck, not even a palette swap. At least in EQ1 the orcs changed colors at higher levels and learned some new spells.
The other issue I had with the game (I played for about a year after it came out) is how hard it was to get on the same server as your friends, I don't know if this is still the case. Also, since the game was out for a year in Japan before here there was a huge power disparity between the US and Jap players. And the final thing I disliked was WHM were less desirable than RDM and you were even less desirable unless you were one of those ugly taru taru things. Which made getting on a team, which was pretty much required to do anything, kind of difficult.
That said, I would love for a FF MMO to come out that's a little more solo friendly. Currently the only MMO I enjoy is the CoX franchise because of how friendly it is to casual play and the fact you don't need the Holy MMO Trinity to do anything.