Disclaimer: I'm not an expert, just an interested amateur wanting to chat and drawing comparisons from past leaps in tech and other conversations/videos.

For a time expert analysis will probably work. For instance, the "click here to prove your not a robot" boxes can definitely be clicked by robots, but for now the robot moves in detectably different ways. My guess is that, for at least a while, AI content will be different from actual video in ways like code. There will probably be an arms race of sorts between AI and methods to detect AI.

Other forms of evidence like DNA, eyewitness accounts, cell phone tracking etc. will likely help mitigate deceitful AI somewhat. My guess is that soon video/audio will no longer be considered as ironclad as it was even a few years ago. Especially if it comes from an unverified source.

There are discussions about making AI tools have a digital "watermark" than can be used to identify AI-generated content. Of course this won't help with black market-type programs, but it will keep most people out of the "deep fake for trials" game.

When it comes to misinformation on social media though, well...it's probably going to get crazy. The last decade or so has been a race at an unprecedented scale to try and keep up with BS "proof", psuedoscience, etc. Sadly those on the side of truth haven't always won. The only answer I have for that is making sure people are educated about how to deal with misinformation and deepfakes - eg. awareness they exist, identifying reputable sources and expert consensus, and so on.