sorry, but magical powers were till now from seperate sources aswell (paladin, druid, wizard, bard, sorcerer, ect), i don't see any difference in that compared to the new system
No. Of the base classes Paladin, Cleric, Ranger, and Druid were all Divine spells. Wizard, Bard, and Sorcerer were all arcane spells. 2 catagories. Frankly I would rather have them go the Arcana Evolved route and eliminate the distinction of Arcane and Divine and have them just be spells. What class you are determines how many spells you have, how you cast them, and complexity of spells you are allowed to cast, while the spell power itself comes from one "source."
With how they set it up you have Martial Power, Arcane Power, Divine Power, then later on you will have Primal Power, Psionic Power, and so forth and so on. It seems every other class is going to have its own "Power" source. Ridiculous.