I have migrated all users who made more than one post to the new forums. Users of the old forums will need to request a new password in order to login, using either your old login name or email address. New users simply register. You do have to provide a valid email address and confirm your registration by replying.
I have migrated most of the relevant and relatively recent messages from the old forums.
There are several themes available. Visit your Profile to try out different themes and let us know any suggestions.