In the meantime, visit http://elinux.org/Beagleboard:BeagleBone_Black_Accessories and the cape page
Approved accesories for BeagleBone and BeagleBone Black
Enclosures, cases and mounting plates
How to get approved
There's no charge for being "BeagleBoard.org Approved", just a verification that needs to happen. There's no promise your product will be approved, but we want people to know to use your product if it is of good quality and compatibility.
First, you'll need to send samples of your product to Robert, Drew and Jason at a minimum so that they can test compatibility. Jason will send you shipping addresses and you can find his e-mail address on http://beagleboard.org/about. The product won't be returned because it will be used in testing future compatibility as well.
Second, if any software is required to support your product, you'll need to make sure it is in the default images built by http://bit.ly/beagle-image-builder.
Finally, you should wait to get a confirmation e-mail from jkridner at beagleboard.org with a vector PDF of the logo for inclusion on your website, package or product.