A few weeks back I recall reading that the 2012 production dates would begin in April. I put an order in for an X5 in late February and last week my CA said my X5 had been assigned a production date in the third week of April. Well, I just called BMWNA and it turns out the car went into production today and will be complete on 3/31. My CA assured me it was a 2012 and the picture below shows on the MyBMW website that it's indeed a 2012.
So....looks like they've kicked in production a little early.