I am more interested in what other classes and subclasses are up for alternative class features. Mike Mearls isn't a fan of the design of the paladin and the bladelock, so they seem likely choices (I'm guessing the bladelock will get a specific magic weapon, ala 4e); also, I notice that there are a couple of NPC warlocks (the fathomer and the spider one that I think was in Volo's) that can assume alternate forms. I would be amused if the alternate sorcerer was all sorcerers wild magic sorcerers, but with different tables for different origins (and hopefully a more dependable way of triggering the table). I wouldn't mind the land druid getting more terrain-specific features. I'm fine with the current bard, but I could see a less magic version.
Here's my 2c on what could be alternate abilities for other classes:
Barb: No idea, I have a barb variation that build up ''level'' of rage when it gets hit instead of spending a limited resource. I love the concept of the barbarian from Dungeon World, where the class is not built for damage but more for a reckless type of character in every aspect of the game.
Bard: Maybe a spell less or 1/2 caster bard with more skill or combat ability. Or activated ''song'' aura with various effects instead of spells.
Cleric: Specialty priest?
Druid: Remove wildshape to add something else. Maybe terrain mastery ala ranger? Or remove spells to go all in shapeshifter!
Fighter: Change the extra feats to something that could benefit non-combat pillars of the game.
Monk: no ideas
Paladin: Remove spells and add short-rest smites with different effects.
Ranger: Mearl's ideas are a good start.
Rogue: Remove sneak attack to increase skills or add a Backstab multiplier.
Sorcerer: Spell points? Or take the unused Mystic discipline to create a spellcaster really different from the wizard.
Warlock: Your ideas are good. I have in my homebrews a warlock class that switch the Patron and the Pact in the design space.
Wizard: Replace cantrips?
