For the music industry, LWDRM means that its copyrights can still be violated when consumers bypass the digital certificate. However, adoption of the system could be a PR victory for an industry that suffers not only from piracy, but also from a lack of goodwill from most consumers.
This idea is from the Fraunhofer Institute, the same people that originally invented MP3. They actually developed the technology for MPEG4, but are essentially back-porting it to be used with MP3. It looks like it's a ways from actually being implemented, and somehow I think that this is just one more attempt to put the genie back in the bottle.
Fraunhofer also talks about having a full turn-key solution, with micro-payments and an online store for sale along with the technology for anyone that wants to implement it.
Related Links:
It's hard to see much that's new in this proposal. If we ignore the newly coined LWDRM buzzword and the accompanying marketing spin, we're left with a fairly standard looking DRM scheme, of the type I call mark-and-trace.