First of all the big four music companies should totally license music to online music stores without the DRM restriction. Jobs's points in Thoughts on Music are well made that the DRM requirement is stifling a huge potential for sales. While they're at it, they should make album artwork available in PDF format and make digital music available in a variety of audio qualities which can carry a modest price difference. In short they should do everything they can to make digital music truly competitive with CDs. However, more than anything I'd like to see the debate about digital music shift away from DRM and technological compatibility issues, and toward the environment. Read on to see what I'm thinking about.
CDs need to be manufactured, packaged and shipped. Often they travel long distances, and the manufacturing requirements are far from modest. First off, the plastic used in CDs is polycarbonate, a type of unbreakable plastic which is also used in bullet proof glass. While you first may think "sweet! unbreakable plastic" you should then quickly think "will last until the next ice age." Next we've got printing liner notes, the materials for the jewel case, and of course shipping (sometime across an ocean). That's a lot of materials, manufacturing, and energy, just to move data. By eliminating the CD and selling music online, huge savings in materials and energy are possible. Consumers could still burn a CD but given how good connectivity is between MP3 players and other systems, is should be less and less necessary.
In short the major record labels should take steps to aggressively reduce the environmental footprint by selling music online.