I preordered via Amazon and played the beta, but upon finding out that preorders get in after prepurchases, I cancelled my preorder and did http://www.amazon.com/Digital-Deluxe-Pre-Purchase-Online-Access/dp/B008MAZ0PU/ref=pd_sim_vg_1
The code was immediately available after purchase in the digital downloads page, plus a $5 Amazon credit code in my inbox, neato.