Shocked: Reduced magic resistance
Burning: DoT
Poisoned: DoT
Weakened: Damage reduced by 15%(certain passives can increase this effect)
Sundered: Armor reduced by 25%(certain passives can increase this effect)
Panicked: Runs around not attacking anything, AKA fear.
Chilled: Slowed
*Frozen: Incapacitated
*Paralyzed: Incapacitated
*Stunned: Incapacitated
*Asleep: Incapacitated, damage taken ends the effect
*The last four status effects are primers which can be "detonated" to achieve cross class combos for significant bonus damage.
I hope I didn't forget anything..