Square Enix Account
I think the latest addition of the SE Web Account system is a move toward what will be used in FFXIV. It makes sense now as it doesn't really do anything right now except test the integration of POL IDs to a web platform beyond the Linkshell community and FL+. They mentioned that your FFXI Friend's list will be transferable to the new game so there you have it. The first beta of the system.
I am hoping for all the POL functionality to be in game and all the account level systems to be via a SSL page. Having to be logged in to POL in order to make significant changes to your account with the added fact that Square's customer support refusing to be open on the weekends makes things a nightmare.
I am guessing that you will be able to access Mail, Friendslist, account info and subscription information via the SquareEnix Web system. However also be able to access Mail, Friendslist, Guild tools and everything else that POL does in game as well but with much better functionality.
Another interesting thing to consider is that the SquareEnix Web Account management system contains very little java and its resolution seems to fit perfectly into a PS3 web browser. It actually resembles the PSN login system a lot. So maybe this is the begining of what you will see when using the PS3 to manage your account.