It seems that the pent up demand for the Bugzilla wikimo integration (aka mediawiki-bugzilla) was MUCH greater than we anticipated. In less than a week, use of this extension has grown to the point where it is affecting the reliability and availability of both our Bugzilla and mediawiki installations. The extension has been temporarily disabled while we make some changes and add some safeguards to ensure that Bugzilla and wikimo remain operational while the extension is in use.

You can follow the work in bug 731672.