@Burning Spear: Technically, no.

Southern Magician does allow you to qualify for the various "Cast Arcane Spells of level X" classes, such as say, Archmage(Of course, you then wouldn't be advancing casting because you didn't have an arcane spellcasting class). Or, from the other side, "Cast divine spells of level X" classes.

However, it does not qualify you as an arcane caster or divine caster.

That said, the DM may have other ideas on that. 3.5 was kind of inconsistent with requirements sometimes.