Every exit poll from last November that I've seen demonstrated clearly that the American people didn't think she was qualified, even for the VP slot.
As long as the American people still elect Presidents, which given the current administration isn't without doubt, the perception by those same people that Palin poses questionable bona fides, will be problematic should she launch another national campaign. To ignore or deny that fundamental truth is whistling past the graveyard.
Simply put, it not a question of "is she or isn't she qualified", it's a question of "what do the American people think about her qualifications?" Thus far, it's not positive.