Jamie, I like this clip design. The biggest issue I've ever had with a deck clip (aside from it being too tight to hold certain decks) is the fact that the protection level offered the box is very low - three sides are exposed. Porper Clips help with the warped-cards issue, but they're more difficult to use and totally ruin boxes, embossed ones in particular. This design looks like it would firmly hold my deck, only the top and bottom of the tuck box is exposed, warping is minimized because both side edges of the cards are getting held down by the clip, and it just looks cool.
My one suggestion - forgo the little slits in the back unless they serve a specific functional purpose. Make the front available as plain or engraved/silkscreened with deck box images, like the front of a pack of Tally Ho, Bicycle, Bee, etc. (assuming USPC would sign off on that without asking for your firstborn son). I just think the surface would look cooler as either a big blank slate or something that could be decorated without the central break the slits create.
As far as custom wrappings, a la Dan and Dave, don't go too crazy. Leather, nice. Carbon fiber, cool. Crazy stuff like expensive leathers, or CORK - noooooooooo...
You might even be able to work with a skin manufacturer like ZAGG to allow people to create custom skins with whatever images they want. It would be no different than making a skin for an iPhone, a Blackberry, etc. Now THAT gives the clip versatility - sell the "blanks" with a coupon code for one free skin from ZAGG, and people can choose others while they're there to suit whatever mood they happen to be in that week.
