Display settings revealed in OS X Lion may indicate that Apple is prepping Lion for retina display in future releases of their Mac range. Advancements in display technology through HiDPI mode (High Dots Per Inch) may see a quadruple increase in the quality of future Mac displays.
According to MacRumors
The 1280×800 HiDPI resolution shown here represents exactly 1/4 of the area of the native resolution of the 30″ Cinema Display and simply offers you a zoomed in view on present day monitors.
The reasoning is that when displays do reach ultra high resolutions and dots per inch (DPI), simply drawing the OS X interface as-is would result in very small interface elements. Apple’s solution is to scale all on-screen elements automatically by a factor of two (in each direction).
So, in the future, we might be using 2560×1600 (HiDPI) mode on a theoretical 30″ 5120×3200 pixel display
Arstechnica posted the below image that shows HiDPI in action. The image shows TextEdit using twice as many pixels as normal.