My exchange had a WBC date of October 2010. Shortly before that date was reached it was removed and now there is no WBC date at all!
In the meantime it moved from Market 2 to Market 3 designation because it now has four providers with equipmenin the exchange, only BT haven't changed the status.
MY BT line sync speed has dropped by almost 1 mbs in two steps, BTR think that the exchange is WBC enabled, but the date for it to happen has been removed and there is no date for that or FTTC.
So BT not only change dates whenever they want, they even change their minds totally.