The CE is basically just the first printing's Anarchy Edition, which buyers got if they bought a copy (Xbox, PS3, PC) when the game first launched. The 'Campaign Edition' of Rage includes all the downloadable goodies that were a part of that printing as well including the extra area.
In RAGE: Campaign Edition you will take on bandit gangs and hordes of mutants with an arsenal of exotic weapons and special items, such as Wingsticks, personal turrets, sentry bots, and remote-controlled bomb cars as you play through the game’s full unaltered single-player campaign. The Mac version will also include bonus equipment formerly exclusive to the RAGE Anarchy Edition, including a Double Barrel Shotgun, the Rat Rod Buggy, Fists of RAGE and Crimson Elite Armor. You’ll also have access to the Wasteland Sewers Missions which feature additional mutant blasting gameplay and looting opportunities.If you've never played the game, Rage features the Tech 5 engine which produces absolutely gorgeous visuals and is actually kind of an 'open world' play style for post apocalyptic warriors to rummage around in.
Rage (which is brought to the Mac by Aspyr) is rated M and also carries a 17+ rating on the App Store, you know- just for redundancy's sake. You can nab it right now for $39.99 right here.