Disney’s initial operating schedule for March 2012 is out, and the Autumn-Winter-Spring Itinerary works for all March weeks.
However, last year as March dates got closer Disney World added a number of 8a openings and additional Extra Magic Hours, especially at the Magic Kingdom.
Therefore, as the your visit gets closer double-check Disney’s operating calendar (or if your date is very close, Next Week at Walt Disney World) to see if you may need to start your day an hour or two earlier than the itinerary says!