And for those poo poo-ing this as poor game design and wanting to keep the old ability the way it is, this is the design the game uses currently. We already have the ability to not invest anything into TU if we want, and instead use the charges for a number of other things. Examples include:
Positive Energy Burst, which heals targets around you and removes negative levels and stat damage.
Divine Cleansing, which removes certain status effects from the target.
Divine Healing, which restores health over time.
Purge Dark Magic, which removes effects from the target.
Martyrdom, which when you are killed expends 4 turn undead charges, and heals nearby allies for a large amount.
Positive Energy Aura, which creates a healing over time zone around you.
Reactive Heal, which applies a buff which is consumed when the target drops below 50% hp, consumes itself and heals the target. It also grants immunity to its own effect for 3 minutes.
Divine Vitality, which restores spell points to the target.
Confront Any Foe, which inflicts extra light damage on a successful hit.