Agree that wireless charging is a must in the Pixel 3. It really should have been in the Pixel 2 to begin with. They are really behind in this respect. It's deeply ironic because the Nexus series from Google were some of the first phones to feature wireless charging (and facial unlock!).
Speaking of, let's see some facial unlock features added!
Wireless charging will likely mean a glass-back design. I hope Google finds a way to keep that two-tone aesthetic of the Pixels. How will they accomplish this with a glass-back design? Different shades of glass? Or will they abandon the Pixel aesthetic and just go all glass in one color/shade (could it look like the upcoming HTC U12)? In other words, I'm looking forward to good design.
And you can't talk about good design without discussing bezels on the front. They need to be improved considerably, especially on the regular Pixel 2 model. Even on the larger Pixel 2 XL, the bezels could stand to be trimmed -- I think they're oddly thick. Also, it's been proven that you don't need front-facing speakers to achieve loud, good-quality dual speakers. They simply don't need to be front-firing anymore. We can give that space back to more screen.
And speaking of screen, give us better quality screens, too. Perfectly happy with them being flat, but it's time to get higher resolution on the smaller model, and I'd love to see Google invest in Samsung panels for both sizes.
Next up is absolutely wishful thinking and has near 0% chance of happening, but I would love if Google brought back the headphone jack. Again, Samsung and LG and others have proven you can have big displays, big batteries, advanced components and parts, and still have room for a headphone jack. Let's stop the lies that Apple started, that there is simply no room for a headphone jack due to how crowded the internals have gotten. No, you just want to sell your bluetooth earphones. It's very frustrating my Pixel 2 doesn't have a headphone jack. I use bluetooth earphones myself, but there are still times when I want to plug in and play, too. There's no reason to take this away other than to push sales of certain accessories. Very unfortunate Google followed Apple's route on this one, especially after making fun of Apple during the Pixel 1.
Lastly, I would love to see Google open up the software a hair more. Let us customize icons or get a little more nuance in the settings/customizations. Let us install icon packs or themes. This is a long time coming and I'm not sure why they're dragging their feet on this features. Stock Android is great, but it doesn't have to be so barebones. I'm happy to see, for example, sound profiles making a comeback in Android P. That shouldn't have gone away in the first place.
There is so much potential for the Pixel 3. I really hope Google hits some or all of these marks.