You can even argue that no class in 4E is nonmagical as the only really satisfactory explanation of encounter/daily exploits which doesn't falls apart is that they are also magic powered.
The thing is, there aren't "spellcasters" and "non-spellcasters" under the Powers system.
Future power sources include elemental, ki, primal, psionic, and shadow.
PHB page 54 identifies the future power sources:
...plus there are the PHB1 arcane, martial, and divine power sources, of course. Of these, the only obviously non-magical is martial. I could see some or all of ki and primal as being non-magical. Psionic depends more on how you feel about psionics, I think. Elemental and shadow would seem more "magic" to me. Of course, it's hard to say for sure until we eventually see the relevant PHB's.