Terminal Reality has made a huge post over on their facebook page:
Terminal Reality is pleased (and relieved!) to announce that a patch for Multiplayer Achievements glitches in Ghostbusters: The Video Game has been completed and tested. It’s currently awaiting approval for distribution, which is likely to coincide with the Xbox 360 firmware update this Fall. The Ghostbusters team would like to thank everyone who has continued in their support of our studio and games.
Actually, the world is coming to an end. First a Ghostbusters patch, next thing you know I will have a job offer. Dark days indeed are coming.