Hi everyone! I just happen to be a beta tester and since the NDA was lifted for purposes of talking about character creation and Gridania, I'm here to answer what I can about the state of Gridania five years later (to the best of my ability... there was a lot of stuff going on).
To answer the question on how vast the devastation was after Bahamut's attack, Gridania is now divided into Old Gridania (an area that will be familiar to 1.0 players) and New Gridania. Unfortunately, I haven't played the original in over a year and do not remember whether there was a "New Gridania" back then, but I'm assuming there wasn't since there is no mention of such a division in the Wiki resources I am using. If the size of New Gridania is any indication of the level of devastation wrought upon the city, slightly more than half of Gridania was destroyed or in need of heavy repair. To give some perspective on the damage, New Gridania extends just north of the large, central Aetherite crystal (the homepoint, not the small ones around town) all the way to the Northernmost edge of the city. It then extends along the horizontal axis all the way from the edge of the lake on the east side of the city to the western most side of the city. If there wasn't originally a lake marking the eastern border of Gridania, I'm happy to inform you there now exists such a lake. A very pretty lake, in fact.
As for the state of affairs, the Gridanians have been working tirelessly at rebuilding their home. The Lancers Guild is up and running at the North-East edge of town along the lakeside; the amphitheater, although demolished, is being hastily rebuilt; and, among other things, the merchants have returned to sell their wares. The seed-seers haven't suffered much of a loss in terms of property damage considering their guild-house happens to be built like a plainsfolk's basement. As you can imagine, the seed-seers have much worse problems to deal with than property loss. You'll hear a lot more about that next month when the NDA gets fully lifted.
_________________
P.S. Hi, Xenedra! I sent you a PM with a link to where the partial NDA lift is described. I also double checked with the resources available to beta testers, and the partial NDA lift is described in there as well. As long as what I'm talking about is within Gridania itself and not some technical aspect of the game (graphics, bugs, etc), I'm allowed to talk about it. However, I cannot talk about the Black Shroud or anything else outside Gridania's walls. I take the NDA very seriously and if my post still makes you feel uncomfortable, feel free to delete it again. Just let me know if you do so I don't repeat anything I've said here.
A link to reddit stating the Partial NDA lift: