That doesn't work for Safari 6 with many sites, which is why everyone is coming here to complain and seek a solution.
Did you read what I typed? "It appears Safari 6 now complies with websites who have "autocomplete=off" hidden in the URL, which is why passwords aren't automatically populating like before." This doesn't mean ALL, but MANY.
Two sites I've encountered, for sure, are PayPal and Craigslist. There are MANY others out there that have "autocomplete=off" hidden in the URL as well (think banking websites). Safari 6 will NOT autofill usernames or passwords for those sites, period.
Do you realize how many times I've clicked on the AutoFill button to be greeted with a message saying no information is available? I've gone as far as completely erasing my hard drive, reinstalling Mountain Lion and restoring from a Time Machine backup. Even THAT didn't work.
This extension, mentioned above, is the ONLY solution I've found since Safari 6 came along months ago. It didn't matter if I was running Lion or Mountian Lion, the problem started with Safari 6.
Again, Safari 6 will NOT autofill usernames and passwords for sites that have "autocomplete=off" hidden in the URL, period. The only work arounds are 1Password ($$$) or this extension (FREE). I'll take the FREE extension.