1. Apple TV - I love my AppleTV ( I have the 4th edition with the old remote), but it resamples all audio to 48k. I want it to do bit rate switching on the fly to take advantage of the better audio capabilities of Apple Music. Outside of that, and the remote they updated last year, I am happy with my current AppleTV, but this kind of update would put me on the upgrade path.
2. Speaking of Apple Music, they need to update Airplay 2 to handle hi res. Well, by that standard, I saw articles last year saying that Apple Music was compressed with Airplay2, so that also need to be fixed (if it hasn't by now).
3. MacOS - Along those same lines, they need bit rate switching on the fly so multi-thousand dollar Macs have the same capability as the cheapest iPad on the market.
4. Apple Watch - I am looking for one single feature that lets me run any app with always on mode. I want to take full advantage of my Clockology watch faces. I will take the battery hit!
5. Homepod - Simply bring back the bigger model and make it cheaper. I have the original and the mini and the mini is not in the same league.
6. iPhone - Better lenses.... more megapixels. I would also love to get rid of the ultra wide lens and replace it with another telephoto. They need a long and shorter telephoto. Personally, I find the distortion on the ultra wide so bad that the lens is mostly unusable.
7. iPadOS / iPad - Please add some version of Final Cut.. and make the large iPad's lighter and thinner (where is Jony Ive when you need him? LOL)
8. Macs - 4k screens would be nice....however, I can't see me updating my 2016 MBP because I prefer using the iPad when I am not in front of larger screens.
I doubt I will update any hardware this year unless I see some of these changes. Just better things to spend my money on than changes I will barely notice or not even use. All in all, the Apple Music lossless/Hi Res release was so exciting, but they have so many products that can't take real advantage of it that it is disappointing.