No, I don't want a screen resolution of half the size, I merely asked if it were possible for our devices, and by your responses seems likely you two haven't a clue. Also, the screen technology is called "AMOLED".
The majority of battery performance is affected by CPU & GPU usage, downscaling the screen theoretically would affect the battery with a significantly positive outcome.
Point is; graphics intensive programs (Bounce Evolution tech demo) would show a noticeable difference in performance, and graphics wouldn't look much different. In other words developers like this guy could see an ideal speed boost in their applications they're developing.