Hi Dan
How are you getting there?? Assuming you are going in one car, you will need one camping pass!
You will be abel to go to one fot he car parks to park your car on the day, and pay a supplemet to park in the Biouac area, so no real panic as yet if you don't mind where you camp. If you want a specific site then your best bet is to kepe an eye on this part of the forum.
There is always "that auction site" as well, but at the moment prices are still pretty silly over on there! Watch it during the last week though and I'd wager that things will get a bit more sensible!
Whether you get a specific camping pass from there or here, or just park i the car park and camp there, the important thing is to make sure you get there! And be warned, once you've been once, you'll be back again and again!!!