ID - not a problem, it lives in my purse, after all.
A copy of the email - I stopped at home to print it out before heading on to Best Buy (then a dinner date)
The Credit Card used to purchase the item - the credit card (low credit specifially for online purchases) that lives next to the computer used to print out the email. The credit card that was STILL next to the computer when I, my ID and my print out were at Best Buy.
So, unless I screw the pooch AGAIN, I should have WotLK tonight.