Sold in separate versions for the iPod nano, iPod classic, and iPod touch, Otter Products' Armor Series and Defender Series iPod cases are finally here. The Armor series replaces the company's earlier "OtterBox" name, but carries on the same drop-proof, dust-proof, and waterproof protective tradition with a hinged and clasped hard plastic and rubber case design. Defender loses the waterproof guarantee in favor of a splash- and drop-resistant shell…