Zepplin CDs -- new box or wait?

Is the new set of Zep CDs -- the "Definitive Collection," I think it's called -- just a fancy set with gussied-up packaging, or are we talking about improved sonics, too? I had thought that when "Mothership" and "The Song Remains the Same" were released (last year?) that those issues were presaging the re-release of all the individual remastered discs. Are we still waiting for that to happen, or did I somehow miss the news?
Thanks.
Howard