A new link discovered by Sander (one of the excellent Googling Googlers who keeps tabs on what they see at Google) in the main Google Accounts page reads "Change authorized websites". The link points to www.google.com/accounts/IssuedAuthSubTokens and displays a page that tells me "there are no third party sites authorized to access your account".
He points out the possibility this could be related to an article I wrote back in February regarding the X-GOOGLE-TOKEN which would allow websites to accept a Google account as a method of authentication. Considering the website this link points to (IssuedAuthSubTokens), I would think this scenario is likely.
If I was to guess how this will be used, "Authorized Websites" sounds to me like a Google user will grant limited access to specific websites for your Google account. Maybe this is what was referred to as "Lighthouse" in the leaked presentation notes describing it as an "Access List"?