Okay, neither part of that one is exactly right. According to the Census Bureau the unadjusted rate of homeownership in the first quarter of 2013 dropped by 0.4 percentage points to 65.0 percent. The seasonally adjusted rate edged down by 0.1 percentage point to 65.2 percent. This may not be a "plunge" exactly, but either way you would have to go back to 1995 to find a lower rate of homeownership. (Can we get Alan Greenspan out here to give us another lecture on the glories of subprime and other innovative mortgages?)
It's also not quite right that no one noticed. There are some business reporters who have heard of the Census Bureau. Mark Lieberman had a piece highlighting the new data.