I really like this idea. I might quibble with calling something you get at level 10 a "background", but overall, I like the idea of adding a new, flavorful, trait and a few more skills in line with your character's accomplishments.
Dragonslayer
Prerequisite: You slew a dragon.
Story: There was a dragon. You slew it.
Trait: You are given the best rooms in inns within 200 miles of a dragon's lair. Nobles in those areas start at "friendly" toward your character.
Thaumaturge.
This is pretty much what they've talked about though, isn't it?
Traits are supposed to be something that you can earn in play - there was talk about how you'd do that when they mentioned the downtime system.
I wouldn't be at all surprised if this is something that they cover in the DMG, at least