A painted staircase "runner" can bring bold color to a small space. Try a shade that links the upstairs and downstairs, or consider a combination of tones that packs a visual punch, such as these stripes.
Unique stairs, I love this idea.but think I would stencil them instead of the wallpaper. I am loving the granite or marble for the stairs as well instead of wood. Oh, so many ideas to put into a new house one day.