Context aware visuals, say looking at a business store front it shows the important details or the menu if it's a restaurant, public transport timetable and route when looking at a station sign.
For navigation, rather than a semi transparent map, looking ahead at your path could display something like the 'racing line' assist you get in games.
A training tool when performing a physical task, say assembly. Each step could be highlighted, tools needed, instructions, torque setting etc.
I'm a quiet person, I don't like using voice assistants/commands, so possibly some sort of eye tracking and blinking to make selections and navigate. Or paired with an Apple Watch as a touch pad to navigate if needed.
Not having anything constantly displayed like a HUD, but with the option to turn things on when you want/need.