Well, wouldn't that just be an entirely different spell then? There's nothing to say we have to pile procs and effects onto an existing one, when we can remove the one you got, replace it with the one you had + the proc/effect you're talking about - named the same, whatever.

I don't think having a different spell is the way to go. Take my necro tank pet spell. I have 6 AAs that effect it in some way. If you create a new spell to replace the starter spell, not only does that mean you now have 7 spells to start, but dozens of combinations of the 6 possible AAs:

ie-
1.) Pet Spell
2.) Pet Spell + Damage Shield
3.) Pet Spell + Damage Shield + Potency Boost
4.) Pet Spell + Damage Shield + Potency Boost + HP Buff
5.) Pet Spell + Potency Boost
6.) Pet Spell + Potency Boost + HP Buff
7.) Pet Spell + HP Buff
and on and on and on...

Then take into effect that each of these AAs has 5+ ranks of power... you are talking thousands of combos.