Mobile Share Advantage

Hey all, I posted about this a while ago but was wondering about an update?  I have the 3GB Mobile Share Advantage Plan and I have hit the cap.  However, I have not been throttled.  I am NOT complaining, as full speed is great!  I was just wondering if there was a date set to when AT&T will actually enforce the throttling feature.  I am asking this so I can tell other users on my account to cut back so we can avoid being slowed.  Right now we're just using data as we please since it doesn't throttle and there's no overage charges.  Thanks!