We use a variety of tools to aid planning and development, including Jira and GreenHopper. In many cases our test cases and design docs will be in our internal wiki, which uses SocialText -- but the exact wiki should not matter.
Would it be possible, using Javascript and Jira's API, to pull in select pieces of information into our wiki pages, for instance the status or description? Doing this would help keep the information up-to-date and would remove the need for manual updates (which usually do not happen, making the information stale).