Microsoft has announced upgrades to its Copilot research assistant that allow multiple AI models—including OpenAI's GPT and Anthropic's Claude—to be used together within the same workflow. This includes a new Critique feature where GPT drafts a response, then Claude reviews it for completeness and citation integrity before it reaches the user. Microsoft says the workflow will eventually run bidirectionally.

The move is a direct attempt to address issues around AI errors (known as hallucinations) and boost the reliability of AI tools—problems that have slowed enterprise adoption of Copilot amid stiff competition from Google's Gemini and Anthropic's Claude. A separate Model Council feature will allow users to compare outputs from different models side-by-side.

Microsoft is also rolling out Copilot Cowork—its agentic AI tool for long-running, multi-step tasks—to members of its Frontier early-access program. The product, based on Anthropic's Claude Cowork, was first unveiled earlier this month.—Beatrice Nolan

OpenAI's abrupt decision earlier this month to kill Sora, its AI video creator, is one of the most baffling developments in the AI business—not least because OpenAI had just struck a high-profile deal with Walt Disney Co. months before.

The Wall Street Journal has new details that shed a bit more light on what happened. According to the report, OpenAI's decision to pull the plug on Sora was as big a surprise to execs at Disney as it was to the rest of us, with many Disney folks learning of the plan less than one hour before the announcement. 

But why did OpenAI kill Sora?

The direct cause was Spud, a new large language model that OpenAI is racing to put through its final training process. OpenAI has a finite amount of computing capacity on which to train its models, and Sora was simply hogging up too many resources for a product that wasn't a priority. 

As for why Sora wasn't a priority, the WSJ reports that usage peaked at around a million users shortly after its launch in September, and has declined to about half that since then. What's more, the hefty computing power necessary to create the videos means that Sora is losing about $1 million a day for OpenAI, an anonymous source told the WSJ. There's clearly still a lot more to learn about the death of Sora (and if you have any insight, please reach out: alexei.oreskovic@fortune.com), but at least we now have a chalk outline of the body and some bullet casings to examine.—AO

Mistral, one of France's top AI companies, has raised $830 million in debt to build a data center about 40 miles south of Paris. 

The AI data center is expected to begin operating in Q2 and will pack 13,800 Nvidia GPUs. Mistral will use the data center to train its latest open source large language models, according to Bloomberg. The company was founded in 2023 by former researchers from Google's DeepMind and Meta, and represents one of Europe's strongest home-grown alternatives to U.S.-based AI giants. As AI tech becomes increasingly important in the global economy and geopolitics, countries across the world are looking at creating sovereign AI and cloud infrastructure. Mistral said it's planning to build 200 megawatts of capacity across Europe by the end of 2027 "to support the demand from governments and enterprises that seek to build and control their own AI."—AO