For those unfamiliar with the Loudness Wars, it is a relatively recent phenomenon in mastering where albums are compressed and limited within an inch of their life in an effort to make the album sound louder than other tracks on the radio or in the dance club. To hear it in action, listen to a song you have from the 80's. Now listen to one released recently and the difference should be pretty extreme.
The problem with this, as you might imagine, is that doing so removes all of the dynamics from the track which not only sounds like crap, but it is physically fatiguing for your ears to listen to. Imagine having a fog horn constantly blasting in your ears for an hour straight and you can see why.
The above picture is one of the new Metallica tracks taken into an audio editor by KVR Forum member 'zircon'. At first, you might think it's empty, with only those few little lines at the bottom left, but you'd have it backwards. The green part is actually the waveform. For shit's sake people, this madness needs to stop. Music was MEANT to have dynamics.