First up, the Buy-a-Box promo, which you can get if you buy a box at KD Games
Next, on Launch Weekend, play in an event and you could pick up one of these:
Finally, participate in a Game Day event, and you could get this fantastic Trophy Mage. Make the Top 8, and you'll get this intriguing Yahenni's Expertise.
And if you win the whole thing? Well, you'll get this: