At @OpenTechStrat, we use Subversion for our internal corporate tree.  We make great use of the path-based authorization (e.g., a contractor might have access to client A's subtree but not client B's).  Also, the ability to update commit messages has been very handy.  Finally, the simpler mental model -- relative to a DVCS like Git or Hg -- has been a help for non-technical people who need to work in our tree.  It's easier to explain SVN.  This is not a git-vs-svn rant, btw: we like Git and use it for our code, which is #opensource.