The spell as it currently is in-game:

The proposed change:
Make the damage scale with caster level. While this goes against P&P, other damage spells had been given increased scaling. This scaling could be capped like the Lesser Orbs are capped.
The scaling could follow orb patterns:" For every two caster levels beyond 1st, your orb deals an additional 1D8 points of damage: 2D8 at 3rd level, 3D8 at 5th level, 4D8 at 7th level, and the maximum of 9D8 at 17th level or higher."
As it currently stands, after around level 3 there is no reason to ever pick this spell whether as a cleric or a bard. Especially as a bard as you cannot swap it out except for level up or the djinni.
I do not believe this change would make either bards or clerics significantly more powerful. Better alternatives, even with the scaling damage, exist. However, it would introduce variety and viability to blaster bards/clerics.