What,REALLY is stopping the major tweams from starting the GPWC sooner than 2008??

[RWC]

Yes,i know they are 'contracted' to the current concord agreement but what does that mean REALLY.Are they actually banned from running any cars in another race series?Surely if they leave f1(notice no capitals),then they could be sued by bernie,etc(and i'm sure bernie would LOVE the chance to get even MORE of someone elses money,LOL).
But what if there is a major disagreement over the way the rules are interpreted??
I'm GUESSING that the manufacturers would still have to race in australia -i use this as an example because of the current talk about it(and take the fia to the Lusane court later-because that's what they're obliged to do under the concord agreement).


***It's easy to see sometime in the future a situation of f1 getting so annoyed with max and bernie's antics that they just pull out of f1,CHANGE THE TEAMS NAMES and set up the GPWC much sooner than 2008***

Yes i know it's nowhere near good,but what technically is stopping them..??