I prettied up my house rules for the Wizard class a little bit and posted them here: Athasian Wizard and Arcane Magic - Google Docs
It includes changes to Arcane Magic including spell points, feat based magic (inspired by Midnight RPG), revamped magic item creation, the preserver/defiler choice, etc.
The overall idea was to make arcane magic (and specifically defiling magic) more “powerful” than psionics. Low level magic doesn’t harm the environment but that starts to kick in at level 3 with 2nd level spells but today’s wizards don’t get as easy access to spells. Preservers intentionally made themselves weaker so they would not harm the environment. Defilers throw caution to the wind and cast spells without concern for the damage they cause as you’d expect.