Jump is a given. I guess the only discussion I can derive from it is how many versions of jump will be available and for what purpose. The classic use was to avoid damage, and exchange several turns for a large damage spike. XI's version was a tertiary move wherein you used it as enmity shed, a slightly boosted attack, and if you were good at timing a way to avoid damage on yourself. I wonder if those same traits will carry over, or if jump will have new varieties.

Nah not really, FFXI is the only game with them and all they do is serve as an excuse to weaken the dragoon itself from a design perspective. (Thanks for the offer, but I'll have to pass.)
I'm not really quite sure you understood the play style and role in dragoon in XI. Dragoon in that game by any means was not nerfed by the presence of the wyvern. Wyvern was fundamental to it's strengths. You had to look at the totaled output of both the payer and the AI. And without going into a long fangirl rant over it, you basically had a melee that because your damage and actions were devided across two separate bodies, your enmity gain was also. The role drg played in that game was to do as much damage as possible without the personal enmity gain other melee classes would get. Pair that with the hate shedding qualities of jump and you were golden. The dynamic of changing the wyvern's abilities with subjobs was also really powerful. Being able to cast equivalent to cure IV for 5 mp cost and zero enmity gain? Awesomely useful if you knew how to take advantage of it.
On my server during my time playing, I was part of the largest NA linkshell. We had basically every endgame or specialty gear availble, and my dragoon was exactly on par in the damage department as our decked out warriors and this was prior to many of the boosts. Adding wyvern didn't make the class weak in any way.

I'd like to bring back wyvern not only for the nostalgia of it, but also all the interesting dynamics it brings to the table. Just having lancer once again with one unique ability to me isn't enough to make the job of dragoon special enough.

My only concern is, as someone else above had mentioned, that the pace of battle in 14 is on hyperdrive compared to 11. Most our room for strategic play or build up is lost to it. That goes for pretty much every class/job though.

I guess if anything wyvern is at least good for a built in always on double attack.