As mentioned on the NSGIC News Blog, the National Agriculture Imagery Program (NAIP) for 2009 will cover roughly two-thirds of the USA. This is quite an achievement for the program and will result in an excellent resource for geospatial practitioners as well as the broader public.
A status update from yesterday indicates that flight operations are already well underway.
Here is a map of the contractor areas:
Note that further maps and status updates are available from the APFO (Aerial Photography Field Office) home page.