Is there even anything in 8k to watch?
Not anything of worth no, just demos really, BC in Japan as Bo says.
The main attraction is gaming for me, you can play anything you want in 8K right now if you have the HW to do it. Even just downsampling 6K or 8K to my 65" 4K set looks absolutely amazing, like the realisation of promotional bullshots in terms of IQ.
Hopefully once emulators like Dolphin are more optimised for 8K output you can do that as well, I played SMG 1&2 in 4K but with 4x super sampling anti-aliasing last year which I think means effective 8K res and the difference between that and native 4K was really noticeable to me. Everything was so perfectly rendered (Well, not everything but I am a big aliasing pedant haha) on a 4K display I can't imagine how good it would've looked on native 8K. I could've just put some high sample count FXAA on it to cover up the remaining aliasing but it scrubbed some super fine detail so I left it off.
If I was setting the emulator up for a normal peep I would definitely turn FXAA on because it made it look like CGI animation, due to being so sharp/clean but with a filmic softness from the FXAA.
edit - this is from a techradar article where they are trying to run it at 8K on a Titan, they left the disgusting, IQ-ruining chromatic aberration effect on so the sharpness is fucked but just zoom in on it and look at the detail, you'd want temporal AA + sharpening on to remove some of the trickier pieces of aliasing like the car boot or transparencies but even without its stunning:
In the article they say it runs at 24ish fps most of the time, yeah that means the cutscenes will be about 12-18 fps haha, not really playable. 6K would've been more realistic for 30fps lock but I think even cutscenes would drop, especially if DoF is on, that slaughters framerate in tricky scenes like close ups of Carlos's hair or just multiple main character faces at once.