Well, I've just installed the new OS X Mountain Lion and surprise!!! There is no SVN on it. Subversion is not included in this new version but developers need SVN as well and not only GIT.
Hope Help!
How to install it?
If you are a iOS developer you are lucky. After install the last release of XCode go to Preferences > Download > Command Line Tools and click on Install. Wait a while (115.4MB) and done! You will have SVN installed in your Mac.Hope Help!