Watched it 2 days ago so I might forget something. But here are the highlights I remember:
1) Paladin will have some sort of RPG leveling system. He has valor tokens (auras) with on each side a power/ability/improvement, by doing certain things he can take earn these tokens and choose a side. The power on the other side will not be available for the rest of the game. By choosing different combinations you can make different builds.
Sounded to me like the Paladin gains "valour" for doing heroic deeds, like attacking the "strongest" creature or spending a guard token to protect a friendly creature in his zone. Then he can spend "valour" to gain "Auras", which are double-sided tokens that can't go away. Since they're double-sided, he has to choose one (that might be a level 1 aura) and can't change his mind in a given match, and the next one he chooses might have a prerequisite, so it might lock him into a certain aura upgrade tree. Think Diablo II.
They have artwork for a mount for the paladin, but will not include it in the set. Mounts will be introduced in a set in the future. (Not only for the paladin but for every mage) Mounts can be, but are not limited to horses.
Bryan mentioned a winged Pegasus, possibly a dragon, etc. I could imagine a dinosaur for a Beastmaster and a pig for the Dwarf Warlord (not mentioned by Bryan, just speculating). Sounded like they've pretty much designed them all already but decided to put them in the "very next expansion after PvS" so I'm guessing it will be the next Battlegrounds expansion... which might not be Archmage then (?).
3) As mentioned before, the siren is trained in songs. Songs can be from every school.
And it sounded like most mages have a relatively small selection of song spells available, while the Siren is trained in all songs.
And then there's
Grapple. It's a keyword on cards including the Kraken (!) and a giant crab that is like Force Crush that makes a creature stuck and takes direct damage. And at least in the Kraken's case, it's combined with Snatch, so the Kraken can grab a creature from a neighbouring zone and hold onto it and crush it using "Grapple." Sounds awesome to me. Oh, and something about Leviathan.
