No talent currently attached, but HBO is moving forward with a Dunk and Egg series. https://variety.com/2021/tv/news/game-of-thrones-tales-of-dunk-and-egg-series-hbo-1234889520/
If they do this right it could be amazing, like really really good. I think this is some of GRRM's best writing, I was very sad when it ended. Felt way too short. I wonder if they would take the series all the way thru the Tragedy of Summerhall, if the established material went well. They could definitely end it that way, with some type of look into the future.
Doing Dunk and Egg is so dumb. It will run into the same issues GOT had. They're gonna run out of source material after 1 season, 2 at most. GRRM said it's supposed to be 9ish novellas. He's written 3 of them
I would argue that the problem with GOT wasn't simply running out of source material. it was a complete lack of ability by the people doing the show to continue the story. if you get the right people involved, they can use the first three books as a launchpad to tell their own story. I can see if you say only GRRM should be telling stories in this world, but he can't finish one either.