Love this idea! Kid's room - not painting all the way to the top and allowing the ceiling color to come down on the walls a couple of inches.using painter's tape for a clean edge. No fussing with trying to keep a clean edge on ceiling border.
We've used a similar corner shelving unit to create space in a small 7 by 9 ft room. It's a great, easy shelving solution for small spaces (although installing it was a bit tricky as the walls weren't plumb.