I'm so excited. Once a decade the census release day comes, and for me its a huge holiday! I am sitting here waiting for the first batches to index and arbitrate to become available.
Ancestry seems to be a bit ahead of FamilySearch in getting the browsable images for each state online.
I had no trouble viewing a census page at Ancestry.com, and havent tried yet on the other sites but I hear that 1.9 million visitors were causing issues for the National Archives. I predicted this, as I expected a huge number of people would want to browse and find their family right away.
As I have posted elsewhere, I will be focusing on helping with the FamilySearch indexing
Ancestry will be indexing the census on their own (Im assuming with their overseas non-English speaking indexing team, more on this later!) and putting it behind their paywall after some time. But for now there is this new Free Access offer from Ancestry.com to help you located your family the new 1940 census before it is indexed: