Resilience: Like defense, resilience reduces your chance to be crit. Unlike defense, resilience also reduces the damage taken by crits. However, since your goal is usually to prevent crits from occurring at all, this latter part seems less important.
* Each point of resilience reduces your chance to be crit by 1% and reduces crit damage by 2%.
* So, for damage mitigation why would you ever be interested in resilience over defense (which, you have to admit, with its bonuses to dodge, parry, and block seems the far superior stat!)? For one reason: defense completely prevents you from being crit. With a high enough defense, you can't be crit. With a high enough resilience you can't be crit, either -- however, with resilience, on crit abilities have a small chance to activate on non-crit abilities. Your on-crit abilities will never activate with a high enough defense to prevent crits. (This is not a bug, as recently confirmed by Drysc.)
* Resilience rating gives you differing amounts of resilience depending on level:
o At level 60, it takes 25 resilience rating to equal 1 resilience.
o At level 70, it takes 39.4 resilience rating to equal 1 resilience.
hum...