Dag Kittlaus, co-founder of Siri, reacts positively to Apple's new AI features announced at WWDC, calling it a great first step for Siri's renaissance. He emphasizes privacy, on-device processing, and the potential to leverage the App Store for cross-app functionality, which he sees as a competitive advantage over frontier AI models. He predicts that on-device AI will disrupt paid AI services by making most queries free.