Feel free to discuss rules and other functional differences here as they become known, but I thought I'd start off with some cosmetic differences (which may or may not be functional differences) that I noticed with the promo cards that come with Academy.
Two things I noticed immediately:
(1) School given in text under the school's symbol. This seems redundant given the symbology is well established in Arena and is still being used in Academy. Does this text ever vary from the symbol above it? Are there other new options? Would "Novice" be listed in this location rather than in the card text - e.g. to make it clear what the spell book point cost is by looking only in the upper-right?
(2) The Gorgon Spearthrower's "Poison Spear" attack shows a new symbol for its d12 effect that resembles a "WEAK" condition token. While this is nice, it takes up a lot more space and probably wouldn't work on cards like Devil's Trident that can cause more than one type of (and sometimes both) condition tokens depending on the outcome of the d12 roll. I'm also a little surprised it doesn't show the damage type of the condition in the symbol (e.g. a poison "skull & crossbones," in the case of "Weak") since that information matters with regards to creatures that are immune to the damage type associated with the condition. Of course, this attack itself isn't a "poison damage" attack, so creatures immune to poison can still suffer damage from the attack itself, just not the condition... and perhaps putting a poison symbol on the Weak token image might have added more confusion rather than reducing it. Still, an interesting choice to include a symbol rather than text for effect die conditions.