Apple has applied for a patent on a desktop Mac design whose main body consists of a single, curved sheet of glass.
The patent was filed with the USPTO in May 2019 but was posted online Jan. 23 2020. It describes "an electronic device that may include a glass housing member that includes an upper portion defining a display area, a lower portion defining an input area, and a transition portion joining the upper portion and the lower portion and defining a continuous, curved surface between the upper portion and the lower portion."
A wedge at the back of the device could both house processing components and prop up the design. A slot at the bottom center would let you slot a keyboard through, and Apple even says that the curve could be altered to adjust the display angle or fold the system shut.
The patent also imagines sliding a MacBook's keyboard section through the slot, suggesting this design could also be used for a laptop dock instead of a full-fledged computer.
This patent application does shed light on Apple's design process, though, and suggests that it's willing to revamp desktop Macs sometime in the future.