Definitely worth a talent or similar-level class feature. d12 damage die (presumably for two-handed weapons only) as an advancement from d10 damage die equates to about +1 average damage, which means it'll give the player an average of +1 damage/level. The cleric Strength domain lets clerics go from d6 to d8 with light weapons and d8 to d10 with heavy weapons, which is an increase of the same degree, and that's a class talent.
Seems like a reasonable talent option for Barbarian, Fighter, and Ranger. I'd try it out tentatively with a player, just in case it combines in an unbalancing way with Barbarian Rage or a Fighter Flexible Attack.
(I would even also look at just porting over the Strength domain entirely for players interested in something like this. +1 damage/level on melee and thrown-weapon attacks, along with feats that give a 1/battle Hit Harder option, is a nice little bump that I don't THINK should be overpowering. I've got a party paladin doing exactly this, minimal house rules needed, thanks to the Divine Domain class talent.)