Earlier quoted context omitted.
It'd be cool with a laptop, but it'll require an extra 20 watts (typical for a ~22" screen) to be sized into the laptop's power brick. Since laptops have pretty predictable power characteristics, the manufacturers don't necessarily give you that much extra. Would we upsize everybody's power cord on the off chance that 1% of people would use it? Or does "bigger power brick" become another configurable option, and user…
I think what will be more likely is the other direction. The monitor powers the laptop. Most laptops are well under a hundred watts and could easily be charged and powered that way.
For a while it seemed like DisplayPort or DockPort might be the one cable to rule them all... USB PD seriously changes the footing of the game. Alas, USB A/V (encoded video to an output device) being completely absent is seriously damning USB's chance to be that one cable.