As an avid genealogist for the past...um... thirty years or so, I have been patiently waiting for the 1940 census to be available to the public.
Following is the initial notice emailed to me from Ancestry.com:
Happy relative hunting.....
The National Archives and Records Administration will open the 1940 U.S. Federal Census on April 2, 2012—the first time this collection will be made available to the public. Once we receive the census, we will begin uploading census images to our site so the public can browse them. Initially, this collection will be what we call a browse-only collection. This means a person can scroll through the pages of the census districts much like you would look at a microfilm or a book. At the same time, we will be working behind the scenes to create an index of the census that will eventually allow people to search for their family members by name as they currently can with all other censuses on Ancestry.com. Note also that the 1940 U.S. Federal Census will be accessible free of charge throughout 2012 on Ancestry.com.