In an open letter to the Warhammer Community Online, Mark Jacobs talked about beta testers and giving away beta accounts.
He said that they simply can't invite such a number of beta testers because accounts are limited. Basically, it depends on the data you provided, as well as the configuration you use.
Still, the number users will gradually increase, so more beta test invitations will find their way to eagerly wating fans. Mark also apologized for the Guild beta being late, and said that it should start soon.