For those that do not know what Heroes of Newerth is it is a stand alone Defense of the Ancients (DoTA) clone set in the world of Savage and Savage 2. That is the best I can do to describe it. I am sure if you search around you can find some images and video of the game.
Note: The game currently has a Windows and Linux client only.
Update: We are all out, congrats to those who did get them.
Update 2: We gave out a total of 20 keys which was more than we originally had planned to. We are now completely out of them. Congratulations to those who got them.