The developer is currently reaching out to Steam requesting more keys. When more keys are received IMCGAMES will distribute a 2nd batch of keys to the rest of the participants.
Here is some quick info to note about the beta:
There will be no distribution of beta keys after registration, and there is no way at this time to register anymore. Countries with local publishers already established will not be able to participate in the closed beta. You will be able to stream video of TOS, but no bugs or exploits may be recorded. Client size will be 5. 5 GB, and a 5GB patch for the tested who participated in the first closed beta.
Hopefully, everyone has registered for their beta keys! Stay tuned, here at GameSkinny for more coverage on Tree of Savior.