It would be cool in the future of this game to see the return of the Two-handed swords and maybe some huge bladed swords i.e. Cloud's Buster sword . Swords like that would be awesome. Also implementing some form of enchantment on weapons to deal like fire, ice, lightning, etc damage and such would be cool to see while also altering the appearance of the blade, for example covering the blade in flames for the fire, blue crystallike aura for ice, and gold lightning bolts for lightning, etc.

Even tho its used in several other RPGs, I think with the outstanding graphics FFXIV has, it would look really awesome.

Also It would be cool to see the return of the samurai katanas and such , just more weapons in general and more unique looking ones. Though I'm confident there will be more in the future, with new expansions and stuff this is just my two cents on what I'd really like to see. :P