I bought my first ever virtual tickets this year and was unable to watch yesterday at all, and today doesn't look good either. At least I can still see them and catch up.
Battle For Azeroth Expansion My first thought was "well that's the most boring expansion idea ever." I never played Warcraft 3 or any of the previous Warcraft games, but it seems as if they may be trying to bring elements of the RTS games to WOW, which may be interesting if they pull it off. I'll wait and see how it plays out.
Classic Servers!!!! There's the glorious reveal. I never played a single moment of Vanilla WOW, so I don't have any expectations that it has to be some particular variant, I'm just really excited to see what earlier incarnations were like. I've never seen Thousand Needles when it wasn't underwater. I'd loved to see Auberdine restored. It still makes me sad whenever I send a character through the area.
Auto-scaling everywhere. I thought Auto-scaling would be a good thing, but in truth, I feel like I'm treading water and never getting anywhere in Legion. I like getting new skills as I level. Gawd, don't let there be some Artifact Weapon equivalent so you don't get to level up yourself (that's how it feels) but your boring weapon gets all the goodies.
PVP Servers gone, except now they're everywhere. I put my characters on non-PVP servers so they don't have to be vulnerable to some nitwit with bullying issues. I hate as it is that you can be flagged PVP under certain conditions. In my mind, the only pvp that should occur on a non-pvp server is in instanced battlegrounds, or instanced anything not part of the general world. If this change removes the chance of being accidentally or otherwise flagged pvp, then fine.
Those are the biggies. More after I get a chance to watch the panels.
Side note: I actually liked Anduin Wrynn in one of the cinematics for the first time since Pandaria when he was a selfish, thoughtless boy endangering his own people as they tried to find and "save" him. Mass rez!