World Tree barbarian looks neat.

The brawler fighter has one glaring oversight: it has no way to apply magic damage while using its class features. They promise to include magic items in the DMG that will allow them to do so (probably gauntlets, rings, etc...) but as it is, the class is essentially useless beyond level 5. Unless you find a magic beer bottle or something.

Warlocks are still gimped. While having Agonizing Blast and Eldritch Spear apply to any cantrip is a great change (edit: though there is a huge oversight still which makes Eldritch Blast still the optimal and obvious choice, namely that Agonizing Blast lets you add the charisma modifier to each damage roll, and at the cantrip improvement levels EB gains new damage rolls instead of extra damage dice like, say, fire bolt), they still lost their short rest spell recovery. If they could use the Magical Cunning PB/LR instead of 1/LR, that might be fair but as it is, a level 20 warlock has effectively 6 spell slots. And they can't even claim that it was to get rid of the short rest because the wizard's Arcane Recovery (which at level 20 can restore effectively the same amount and level of spell slots as the warlock's Magical Cunning, btw.) is still tied to it. (Also, while there are many Eldritch Invocations that give warlocks a free utility spell, the wizard's level 18 feature effectively gives them two of these for free, and they get to select any spell.)