Our recent beta key giveaway highlighted that interest -- we had 1,000 closed beta keys, and they were gone at no time at all. We got in touch with the folks at Square-Enix, who generously provided us with 1,000 more keys to share.
The process is the same as last time -- claim your key at our Wakfu closed beta giveaway page, then visit the game's site (note that these are the NA servers) to create an account. Once you've done that, go to the code entry page, log in, and enter your key.
Once that's done, you are free to install the game and play Wakfu!