I have a nook in my new apartment, 27" wide, 25"d 33"h, but that is a difficult niche to fill, most shelves I've found are 30-32 inches wide...
I would try to build something, but being a city slicker here, I have no power tools at the moment.
I was thinking something simple like this, but cannot find one at only 27 inch width... not at home depot, the container store, bed bath and beyond, ikea... nothing fits!
If you're thinking of display for teaware, keep in mind that most teaware is small. Wasted space is to be avoided. In Asia, items are displayed in cases such as this Korean made case. They are usually affixed to a wall so there is no danger of falling through the other side. The beauty of wood, either rustic or finely finished is a matter of taste but usually works well with all kinds of teaware.