The source code for Spring Security OAuth has moved to https://github.com/SpringSource/spring-security-oauth. The old gitorious repository will be removed and replaced with a placeholder pointing to the new one, and probably eventually deleted. As with other projects moving to Github we hope this will stimulate more community contributions.
If you have existing clones you can switch just by adding a new remote, e.g.
$ git remote rm origin
$ git remote add origin git://github.com/SpringSource/spring-security-oauth.git