I would love the return of the draw-on-a-page feature in Edge. As for AI, I’m looking forward to offline functionality to give desktops a way to keep thriving.
In terms of Windows as a whole, Windows 11 had a good thing going with redesigning old visual elements to match the new style, so I hope Windows 12 keeps that going.
On the more farfetched side, maybe a new 3D builder-type app that lets you make shapes from scratch? Or an official way for themes to change the visual style - both would be superb!