There were a few issues affecting new user registrations on the new site after it was activated on Monday. These have now been fixed. User registration was successful, but outbound email was not sent.
If you tried to register and failed to get the confirmation email, please click on the “Request new password” link over there in the login box (upper left area of this page). Then enter the email address you used on the site and click the button. You should get a new email with a new password fairly quickly. Apologies for any inconvenience caused by this issue.