So as you may imagine, design for manufacturing with injection molding is significantly different from working with 3D Printing. You don't need to worry about draft angles, sink marks or fill problems when you are 3D printing. The biggest issue you usually face with 3D printing using fused deposition modeling is bonding between layers, and the resulting loss in strength. However, boss design can be a problem for both.
The design of A Case has gotten about as far as it can with 3D printing. Due to the costs of 3D printing, the current designs are fairly impractical. Therefore, work has been progressing on redesigning the case for injection molding. While the initial costs for injection molding are very high, the per unit retail costs should drop down to a reasonable $19.95.
The final version will come with a clear front panel instead of the smoke colored panel shown in the rendering. The back panel will be laser cut with holes for the USB and power connectors. I'm working on some ideas to hide the screw holes on the top that will probably work out well.
A Case is being designed to hold a common LCD display module and/or a protoboard (72.5mm x 47.2mm). If you have a display that you would like to see fit, that is similar in size please add a comment or send an email and maybe it can happen.
The case is specifically designed to fit a reasonably sized shield in addition to the Arduino. The Ethernet Shield is the reference standard for "reasonable", but most shields should fit. Right now the case is 120mm x 88mm x 56mm and the display pcb and protoboard are separated by 10mm. These dimensions are not finalized, so if you have suggestions please give them sooner rather then later. If there is demand for other Arduino compatible boards to fit, that can probably be worked out.
There should be a system for pre-orders worked out in the next several weeks. The initial run of cases will be probably be gray, since thats the easiest to both paint black and to paint white, but other colors possible in the future.
Also, if you have been wondering where the weekly things are, you can expect them resume after the injection molded design is finished.