Requirement: Must use the power with a simple weapon.
Target: One creature
Attack: Strength +1 vs. AC
Hit: 2[W]+2+Strength modifier damage.
If you're wielding your weapon with both hands, you gain a +2 bonus to the damage roll.
Effect: Until then of of your next turn, you and each ally within 3 squares of you can make attacks against the target's lowest defense instead of the defense normally targetted by the attack.[Dr400:28]
Sundering Might is a 1st-level cleric encounter attack power, which inflicts regular damage, and also allows attacks to be made against the target's lowest defense. It was introduced in Dragon Magazine 400 article Battle Cleric Options.
It is rated as an excellent choice due to high damage and making a given target easier to hit (especially with weapon attacks.) [Charop cleric]