I haven't played it but supposedly Asheron's Call has this kind of feature.
From what I have heard, if you are faster than a mob and are running away
from it, after a certain amount of time it will lose interest in you. I
would assume EQ programmers could figure out a way to implement a similar
feature in EQ if they wanted to. Question is do they want to?

Galtin of E'ci

> The real solution is a time-based hatred demotion system,
> where a mob's hatred for you (as well as your kill-credit
> potential) declines over time the mob is not being attacked.
> Yes this would be difficult; but if you're going to fix
> something, fix it right. Unless the problem is very
> detrimental to the game (which feign death wasn't), don't
> waste time going from one broken state to another broken
> state.
>
>