We are currently trying out the Subversion (SVN) plugin within a test environment of Jira 4.2. While it appears that the plug-in will do the job of providing a dynamic interface between the two systems, we can't find a way in Jira of being able to query issues using the SVN Commits details and hence add them to a filter/provide extracts/etc. It doesn't appear as though you can even do this with JQL?

Without this facility it somewhat limits the benefits of having what looks like a very useful tool as we can't do anything with the information that it provides.