I'd like that too. Okay let's be optimistic, and change my "not likely to go dark" to "doesn't have to go dark, but would be cool if they did"
Let's start with #1, since I've talked about this common misconception many times before. Tired today, so I'll repost one of my previous explanations:
It all depends on what the resting mode of an LCD panel is, black or white. That is, whether the crystals default to passing light up through the second polarizer, when _not_ activated by power.
While older type (e.g. TN) LCDs do usually default to a white resting mode (meaning it takes slightly less power to be all white), and that's what most people remember from years ago...
... IPS LCDs such as used in the iPhone default to a black rest mode. Thus, just as with OLEDs, it takes more
power to activate the crystals to let the light through to make a white screen.
Moreover, unlike OLEDs, LCDs used in mobile devices have backlights that are always on with the display. So both all white or all black (more like all grey) still takes the same backlight power.