With VIP Access on LttD you will be able to see all the VIP Member forums that are now locked for you. You can continue to use the Private Message system and you have access to the Arcade again. CoS Members need a VIP account to access the CoS Members Only area on the Message Board.
Magister Ventrue announced these changes about half a year ago in the following posting: LttD changes this weekend
To become a VIP Member you need to sign up on Undercroft
and buy a subscription from there.
In order to gain VIP Access and/or CoS Members Only access you will need to create an account on the Undercroft and purchase your subscription from there. Once you do you will receive information on how to get your account on LttD upgraded as well.