Personally I think wings look hideous most of the time, and something like aerial combat just doesn't sound appealing. I'd be fine with wings if they're completely optional and effectively just a mount, but forcing players to use them because they start putting gathering nodes at the top of the tree rather than the base, or having aerial fights? Meh. I just cannot see aerial combat being worthwhile, it doesn't really add anything new and it would either look awful or require a massive amount of new combat animations to pull off...

Now, if you were to suggest a Skies of Arcadia clone with airship combat, that is an aerial combat system I can get behind. Aerial combat with wings would just let us fight Wyverns in the sky the same way we fight them on the ground, aerial combat with airships would let us take down enemies like Bismark and Bahamut, perhaps the odd Garlean Dreadnought.