Several blogs are now writing about this, but what's missing from my mailbox is anything from Citi. My guess is that AA went public sooner than Citi expected, and that most of our questions will be answered when Citi makes its announcement, unless I overlooked it?
It does seem that way as there have been no changes to Citi's online marketing materials for the card, and the bloggers (some of whom have contacts within AA and/or Citi) have only been referencing the fact that AA.com has been quietly updated to reflect the new Admirals Club access rules for Citi Prestige cardholders.
What is a little odd is that (a) reports are that Admirals Club agents were briefed on Saturday regarding the new access rules, which are already live and (b) this timing coincided exactly with the discontinuation of access for Amex Plat/Centurion. One would think that Citi's marketing team would be more on top of this as far as making an official announcement?