It seems to me that the cons far outweigh the pros here, cons being: increased costs, trapezoidal issues when throwing to a wall (requires machine vision to map wall and adjust dynamically), durability issues, input issues (impede image to adjust OR interact with device, which will shake the image), lighting requirements. Plus, exactly how often does the situation arise where something needs to be shown and there isn't a suitable screen around? We have laptops, iPads, and often the smartphone's screen suffices.

Apple are wizards though, and if they can do the impossible here then it will be a huge score for their hardware/software advantage.