I like the Inverse Combat Expertise idea. It would allow tanks that would be pretty much screwed against high-level opponents (who only miss on a 1), to potentially use both PA and ICE to sacrifice AC (which they weren't using anyway) for damage with no net penalty to attack.
Sacrificial Stance [General]
You know how to expose weaknesses in your opponent by showing weakness yourself.
Prerequisites: Dex 13, Armor Proficiency (Heavy)
Benefit: When you use the attack action or the full attack action in melee, you can take a penalty of as much as –5 on your Armor Class and add the same number (+5 or less) as a bonus to your attack roll. This number may not exceed your base attack bonus. The changes to attack rolls and Armor Class last until your next action.
Special: A fighter may select Sacrificial Stance as one of his fighter bonus feats.