This will be tossed, since prior rulings allowed the purchaser of a cassette to make a back-up copy of the cassette for personal use due to the fragility of the tape itself.
Tapes disintegrate after time, CD's don't. So, the comparison is certainly not that easy to make.
Still, I don't expect this to go forward much, mainly because of the infamous "time-shifting" precedent.
CDs certainly do lose quality after long periods of time due to changes in humidity, temperature, sunlight, and simply by being played. Also, any scratch destroys the sound.
Keeping the original CD in a safe place and copying that music for other uses whether it be another blank CD to play in your car or at home or putting in on your computer and then your MP3 player should be completely legal.
In fact, iTunes tells you to make a backup copy of your music files every time you download from them. Is iTunes condoning illegal behavior?
The record companies are being completely unreasonable to the point where I hope they fall hard. I hope artists start marketing directly to stores, which is becoming easier as our retail choices shrink.