Trait improvements: what do you think it's gonna be?

I’m curious about the traits improvements.

I would like to see sims being able to develop traits over time but in order for that to work in a meaningful way the entire ai and emotion system needs an overhaul. I also don’t mind the addition of moodlets as long as their description is also reflected in the sim’s actual behavior.
Basically I’m hoping for more “show don’t tell” in TS4.

Looking forward to seeing what this is all about.