LCD/OLED displays are hardly usable outdoors or in well-lit spaces, unless you live in a very dark place geographically. They need to become at least twice as bright if not more to be pleasant to use, and by that point battery life and heat starts to become a problem.

But if they are able to make it, I'm all the happier. If Apple manages to make a fully daylight compatible device (whichever display technology), then they will have unlocked sales of hundreds of millions of devices. Because who doesn't want to get out of the cave?