This issue may seem small and legalistic but actually it is very important to us all, as SS tried to indicate.
In the 1970's the NFL was not exactly like, but kind of like, a slave set-up. The owners were gods who could pay much smaller salaries relative to today and keep players forever because there was no free agency. Teams stuck together more but you also had downsides like Archie Manning's spending his entire career on sucky teams because he had no option to move. And training camp holdouts were more common because that was about the only leverage that a player had. Then a series of legal battles surrounding anti-trust law moved the advantage in the players' direction, resulting in free agency, high salaries, etc., as well as "parity" (to the extent that it exists). What this case will do, possibly, is undo all of this history and make owners football gods again.
I'm not a legal expert and I've never linked to PFT before, but Florio was a lawyer before he ran a football Web site, and he has more information
here.
As legalese as this all may seem, this case could dramatically change the way that the game we love is played.