GPT-4 is out. There's also a LessWrong post on this with some a lot of discussion. The developers are doing a live-stream ~now (yesterday).
And it's been confirmed that Bing runs on GPT-4.
Also:
Here's an image from the OpenAI blog post about GPT-4:
(This is a short post.)
Is it a pure coincidence that 3 prominent LLMs are announced on the same day?
The other alternative was that there was some coordination about releasing LLM. Plenty of people argue that they somehow should coordinate, so it would not be surprising if they actually did it.