I do like that FFXIV teases things, rather than stating them outright. I'm a little tired of everything in WoW being revealed and data-mined months in advance.
Apparently, Viera (some sort of bunny race) was strongly hinted at. Yoshi-P wore a Bugs Bunny t-shirt, which is as close to gospel as FFXIV gets.
There are multiple classes coming, including Blue Mage:
FFXIV does like flamboyant casters (see Red Mage).
Blue Mage is actually coming out in Patch 4.5, but has a level cap of 50, which will be raised later. It's a little unsure what SE has in mind here. Is it like a preview, do they think they won't meet the 4.5 deadline with a full class, are they dealing with balance concerns? The last class they released in a mid-expansion patch was Rogue/Ninja, and that did have a lot of balance issues at first.
It's also possible that this isn't a regular job, but more something meant for solo play.
All in all, Shadowbringers looks pretty interesting. It sounds like the major story arc with the Ascians that started in 2.0 will come to a close. And it continues FFXIV's focus on story and traditional dungeons.