Lightning's Quest Trailer

[Andromeda]

Confirmed a while ago as a cross promotional event for FFXIV and Lightning Returns: FFXIII, Lightning from FFXIII will be appearing in FFXIV. The details on the event is not clear at the moment, but the trailer helps to shed some light. It shows several enemies from FFXIII and even Caius' dragon (Bahamut-like) form. It also showed Odin Lightning's summon from FFXIII. Given what is seen, it will likely be a series of quests rather than a FATE.

Completing the quest(s) with Lightning will give female players the Lightning costume from FFXIII while male players will have the Snow costume from FFXIII.

[Kurt Zisa]

I think it would be cool if they did other Final Fantasy based missions too, like a SeeD exam maybe where you free a town or village from an invading army. Or where you defend a castle from an armada of airships.

Of course I have no idea of any of that would be possible in XIV.

EDIT: The post you made about the Crystal Tower mission and the Cloud of Darkness kinda answered that question lol

[Andromeda]

There is a plan to add the Golden Saucer at some point. I wouldn't put it past them to add things like Balamb Garden and other iconic things from past games.