A brief update on the Guild Wars 2 Facebook page:
Yes, beta invitations have begun going out. They’ll be sent out over the next few days. Please remember that discussing the beta in any way, shape, or form — including your status in it — is a breach of NDA. Don’t risk your beta access!
So, a reminder that even if you get in, you can’t talk about it without violating your Non-Disclosure Agreement. Don’t risk your access to the beta by breaking the NDA. Keep your excitement down to a dull roar and have a great time in the event. Don’t ruin it by getting booted out for boasting.