As a bonus to returning Magic: The Gathering players, a free deck key will be granted in Duels of the Planeswalkers 2013. I discovered this when first booting up my review copy from Microsoft, discovering a message of thanks for my continuing patronage.

You can use the key to unlock a full deck right away, including all of its 30 unlockable cards, or you can turn all of your cards in one particular deck into foils.