Deposit systems with standardized containers would be my wish. And I wouldn't mind if some of the standardized containers were made of plastics.
I'd also hope for all sorts of concentrates and powdered drinks to take over. A large portion of the packaging we go through every day is actually for drinks.
Single-use bioplastics and fungi-based materials may also be part of the solution. Bioplastics would ideally be created from byproducts of other processes though.