John Siwicki discusses the highlights of OpenAI's dev day, focusing on the new updates and features. He mentions the launch of GPT-4 Turbo, a larger model with a 128K context window. He also talks about the new Assistance API, which allows users to deploy their own assistants or agents. Additionally, he mentions the availability of DALL·E Three in the API and the introduction of the Text-to-Speech Whisper API. John also discusses the pricing for GPT-4 Turbo with vision, the upgrade to GPT-3 and a half turbo, and the new features in the GPT interface. He concludes by expressing his excitement about the potential of these new developments.