This means, that going forward you always log in to the web tools via the billing system, and you do not need to copy/paste the key each time. You can log in by pressing the “Sign in” link in the upper right corner of the web tools. The logger still uses the key for security reasons.
Additionally the inner workings of the login page have been re-designed, and it now allows you to store the username and
password in the web browser (I would strongly recommend setting a secure master password for your web browser though).