I was astonished to just discover: the Hammond 1591XXE electronics box is a lucky near-perfect fit (!) to enclose the rear of the Raspberry Pi 7-inch touchscreen display:
http://www.amazon.com/Enclosures-Boxes- ... B00HKIXNGI
I found that by simply nibbling off the center screw receptacle posts with diagonal cutters, everything clears inside, and there's ample room for all the boards and many optional attachments. The rectangular size of the glass lens (bezel) on the Display is a near exact fit to the box outer dimensions.
Fastening it together as a rigid assembly is a challenge, because the Display design (raw parts repurposed from tablet assemblies) doesn't provide much convenience in that regard. You could improvise with strips of electrical tape, rubber bands, Velcro, etc., to fasten the glass to the box lip on the outside edges, but that's untidy. You could drill the back of the box to fit the Display's rear hole pattern, and attach with standoffs and screws, although the standoffs would have to leave the box spaced away from the glass, as more of an open cover, to avoid putting bending force on the glass, and to avoid putting traction on the glass-to-LCD adhesive.
With the box as a rigid assembly to the Display, you could drill a VESA 75x75 or 100x100 hole pattern in the back of the box to make available all those wonderful VESA stands and gadgets.
What I wish for is a Hammond type box supplied with a special pre-cutout lid with grooves that captured the edge of the glass, like the bezel that every tablet employs, and used that principle to make a firm attachment to the display, with the box part readily removable. This would protect the vulnerable glass edges, assemble everything robustly, and allow for quick opening.