I just wanted to reassure some of you here.
That "parc saturé" signs are very rare. Furthermore, "parc saturé" does not mean "parc complet" (park full).
I've been working as cast member for approx 10 years, this situation already occurred approx. 10 times in DLP's history. Furthermore, remember that untill 2002 there was only 1 park.
In any case, it's true that both parks were really closed to reach their maximum capacity on Nov 29th & Dec 5th.
If parks are full, gates are closed and nobody is allowed to come in until the number of exists is enough to go under the max. capacity. When gates are beeing reopened, people who stay in Disney hotels and/or own a dated ticket are allowed to go in back first.
This situation may provoke situations but just understand that Disney is not comfortable with "casting away" its guests. The only explanation is that Disney is supposed to respect security regulations that limit the number of guests "in-parks".
Of course, I totally understand that someone driving 300 miles and beeing rejected is not satisfied so park management do his best to find appropriate solutions but one more time it is not happening every month.