Linkin Park are planning to upgrade and move to a new platform in the upcoming weeks. As per what the email states, you need to use your email address to activate your new account, and must make changes to your account [if necessary] before August 14th otherwise you'll have to wait till around August 29th. You'll receive an email on August 29th with instructions on how to activate your account. LinkinPark.com however will look the same.
Changes:
[Removing] Friends List, Direct Messaging (for now), old comments and tiny chat.
[Adding] Fan Posts, similar to a tweet or a short post
[Adding] Likes / Shares / Commenting on news and content
[Adding] Connect your Social Media to your LinkinPark.com Account
[Adding] Brand New Contest Widgets
Introducing a new iOS and Android App to replace tiny chat
As per what the email states, all your account information, including forum posts and points will me moved to the new service.
Edit: Incase you didn't get the email, http://lprk.co/2ihqp3
Full Email below: