I probably am the only person who's imediate reaction was "Cardboard of course. Do you even have to ask? Where is your ecological sensibility? Plastic jewel cases are not biodegradable."
That was my first reaction.
The second reaction was "...They'll have to chop down trees to make those cardboard boxes though... Still, a green box is better than a plastic box and for the manufacture of that they would still ruin the environment and end up with a non-recyclable poduct..."
Thought three: "People are used to jewel cases now. The cardboard box will be unusually oversized... oooh! Flip out front!"
Thought four: "Maybe they should go cardboard box with the pledge to plant a tree for every box sold..."
Thought five: "With store shelves adapted to jewel cases, will the cardboard box even fit in the shelves? Or will shops de facto give it a special place because ti doesn't fit in the normal ones?"
Thought six: "Maybe i should be 1 tree per 10k boxes sold..."
Thought seven: "What size will the cardboard boxes be? Will it be same height and length as the plastic, just double width? Then it will fit the shelves I guess..."
Thought eight: "Maybe it should be more trees. We need to plant a forest. Wood elves and pixies need homes too! The Obsidian Forest retirement home for Woodelf and other Woodland NPCs."