The new site is partially active
To clear up some confusion:
To log into the forums
Click on the "Forums" link in the menu. This will take you to what you are used to and allow you to log in using the same username and password you have always used.
To log into the website
Use the form to the right. It will require a new registration.
Soon, the site will use one login for all features. Until then, there's no reason not to be registered for both.