Yes, the Hive has always had Subversion repository hosting. It's not obvious, but it's true.
You can see what repositories already exist by looking here: websvn.oehive.org.
It's not integrated into Drupal in any way, at least not for now. The plug-ins that we looked at for integration were rather immature and not very compelling. We'll have to find some way to make it more obvious that SVN is available on the Hive.
A few of the project pages (like Prolint, ProRefactor, and PDF Include) have descriptions of how to access their own Hive SVN repositories. For example, the URL for ProRefactor's repository is:
Creation of a Subversion repository is a simple automated process. Send me a message with your desired Subversion repository name, and I will automatically create it for you. :)