The plexi case consists of two sheets of plexiglas held apart by stand-offs, and the Stribe innards go in between. Check this post for some drawings of the plexi case:http://soundwidgets.com/smf/index.php?topic=46.0
The sides, front and back are open. This gives it some protection, and looks more complete than a caseless prototype. The idea with the open sides is that it doesn't imply that the device is "finished", you can still see how it is put together, and it allows easy access to the prototyping area for any connections potentially added by the user. It is also a nod to the "open source" philosophy.
I'm also working on a design with a woodworker that will be a slab of butcher block that has been routed out to accept the stribe innards with a window in the top to provide access to the touch surface, and a plate on the bottom to seal it. This will be a much more closed type design, but will still leave the back open to allow access to the proto area and any connectors potentially added by the user (such as MIDI or CV). I imagine this as sort of the Executive model.
I should have some real cases within a week or so and will put up some nice pictures, but I wanted to offer them here as an option.