Its the color commentary for me that distinguishes the spell casting classes from psionicists. The ModernAGE Basic Rulebook defines magic as Arcana and Psychic Powers but it doesnt make much distinction between the two outside of (and I'm paraphrasing) Arcana is magic spells and Psychic Powers are powers of the mind and its left up to the GM and player to fill in the blanks. This has been the case for most RPGs Ive read and played, so in the long run I guess youre right that it doesnt really matter much and it gets harder and harder to come up with ways to make them different from magic.
There absolutely are ways to make the distinctions significant, but you have to get into the guts of them and the system has to have enough overhead to support the differences. Far as I can tell, AGE is not that game.