The future of ai generated content and entertainment is going to be wild! How long before we have ~unlimited high quality entertainment? Before an AI can generate infinite episodes of your favorite show, podcast, comedian, and so on. Going to be an interesting thing to watch unfold.
It's hard to say because even a model like GPT-3 is limited in its ability to generate a textual story that remains coherent over time. When you're talking about generating video, you need to have lots of story and visual details remaining coherent over a very long time horizon. Generally speaking, I think this is an area where deep neural networks are fairly weak and symbolic AI shines. It's much easier to program a symbolic AI that generates a story that remains coherent over time. Though you might argue that the story probably wouldn't be very interesting. There's probably something to be done with a hybrid model that uses symbolic AI to enforce coherency constraints, and a deep network model that fills in details and generates visuals.
So yeah, I think we'd need new, much more sophisticated architectures. We'd also need a lot more compute, like 10x, 100x or maybe even 1000x more, to generate high-resolution video. Actually, the problem is probably not the amount of compute you need for inference, but the amount of compute you'd need to train a model with hundreds of billions of parameters or however much is needed to make that happen.