Here's what the special version, which costs $79.99, includes:
10" Replica Purity Seal
Pack of 25 Premium Character Info Cards
There's a range of pre-order DLC as well. Yet again, there's different stuff for different retailers, so choose wisely!
GameStop: Emperor's Elite Armor Pack (armor skins for the Space Wolves, Black Templar).
Best Buy: Traitor Legion Pack (armor skins for The Emperor's Children, Iron Warriors).
Amazon.com: Golden Relic Chainsword.
Walmart: Golden Relic Bolter
Steam: Blood Ravens armor skin and free copy of Darksiders for PC.
THQ's E-Store: PowerSword multiplayer weapon.
Select PC digital sellers: Free copy of Darksiders for PC.