Amazon Web Services is moving code hosted at GitHub to a new GitHub organization: http://github.com/aws. Nothing is lost. Only moved.
Simply update the URL of the repository's origin:
First, back up a few commits:
$ git reset --hard d005dde1ac04566d9564b36436aa8f2f8db7657b
Next, change then URL of origin:
$ git remote set-url origin git://github.com/aws/aws-sdk-ruby
Verify it worked
$ git remote -v
Pull the latest changes
$ git pull
Lastly, move your local repository to the new name (without the "for")
$ mv aws-sdk-for-ruby aws-sdk-ruby