It's never too early
Honestly, I started planning in August 2012 for last Wacken. Of course I had 3 weeks of trip to fill in as well as all the stuff for WoA.
Why not rent a big tent and have your friends join you? I guess it depends what kind of person you are. If you like to party all night and drink and don't mind being kept awake by drunken people then the normal campsites are fine.
Personally I'm old. I was there to enjoy the concerts and the atmosphere and not to be listening to drunk kids all night
The rental tents were great - you can request a site on the edge of the area which is the most quiet place..relatively speaking because you aren't really going to get 'that' quiet. It's also closest to the infield and the flush toilets which means unless you have to go in the middle of the night you won't have to deal with the dixies