That would be very cool. I bet any company that used that type of plastic would tout it in marketing. The iPhone case from BioSerie in this article does just that, right?
The Vers iPad Case materials, from the Vers site: "The Eucalyptus and Pine wood stock chosen for MDF core of Vers comes from locally sourced and managed plantations near our factory; any trees that are harvested are replanted. Since it’s the wood fiber we’re after, the entire tree is used: trunk, roots, bark, branches and twigs – nothing goes to waste. The wood fiber production system is geared to handle smaller diameter stock typically less than 5 years old; no old growth, threatened or endangered wood materials are used anywhere in our process. Even our furniture-grade veneers are selected from among the most commonly available agricultural wood species on the planet. In the end, the wood used in a Vers system replaces 80% of what could have been plastic. When selected with care, wood is the most renewable material available."