National Archives records can now be accessed at WorldVitalRecords.com. A note on the website states: "These databases, including more than 10.2 million records, are being posted at WorldVitalRecords as part of an agreement with the National Archives. The databases, including the Irish Famine passenger and ship records, World War II Army Enlistment Records, Korean War Dead and Wounded Army Casualties records, and other military records, will be available for free access through April 6, and will then be available only to subscribers".
This arrangement allows better and quicker search results searching across all of the databases collectively. For the NARA records only, they're still available free online at Archives.gov .