AI News Roundup — April 4, 2026
Google launches Gemma 4 open-weight models under Apache 2.0, OpenAI fully retires GPT-4o, and a wave of AI legislation sweeps US states including Tennessee banning AI mental health impersonation.
Google Launches Gemma 4 Open-Weight Models Under Apache 2.0
Google launched Gemma 4, a family of open-weight models spanning edge devices to data centers, licensed under Apache 2.0. The 31B model ranks among the top global open models, featuring advanced reasoning, multimodal capabilities, and support for agentic workflows.
OpenAI Fully Retires GPT-4o From All Plans
OpenAI announced the complete retirement of the GPT-4o model from all plans, effective April 3, 2026. The move marks the culmination of a phased retirement process that began on February 13, as OpenAI pushes users to GPT-5.4 and newer models.
IBM and Arm Partner on Dual-Architecture Enterprise AI Hardware
IBM and Arm entered a strategic collaboration to develop dual-architecture enterprise hardware that can run AI and data-intensive workloads with greater flexibility, reliability, and security. The partnership builds on Arm's recent surge as the leading AI chip architecture.
OpenAI Acquires Influential Silicon Valley Talk Show TBPN
OpenAI acquired TBPN, a tech-business talk show that had become unusually influential in Silicon Valley. The show was profitable with about $5 million in 2025 ad revenue, marking an unusual media acquisition for an AI company.
Tennessee Bans AI Systems Posing as Mental Health Professionals
Governor Bill Lee signed SB 1580, prohibiting the deployment of any AI system that represents itself as a qualified mental health professional. The law is one of the first state-level bans targeting AI impersonation in healthcare settings.
Wave of AI Legislation Sweeps US States
Beyond Tennessee, a surge of AI bills are moving through state legislatures. California ordered agencies to develop AI contract standards addressing CSAM generation, civil rights violations, and unlawful surveillance. Multiple states are racing to regulate AI before any federal action materializes.
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Google's AI Push Could Produce Surprise Investment Winner
Motley Fool analysis suggests Google's latest AI developments, including Gemma 4 and continued Gemini advances, could produce an unexpected winner in the investment landscape as open-source AI shifts competitive dynamics across the industry.