Hi, a couple of our colleagues wrote Huddle Chat in their spare time as a sample application for other developers to demonstrate the power and flexibility of Google App Engine. We've heard some complaints from the developer community about it and because of that we've decided to take it down. If you'd like to see more sample applications written on Google App Engine please check out our documentation and our App Gallery.

Thanks, The Google App Engine Team

Seems they did not want to deal with the criticism over the similiarities between it and campfire (http://www.readwriteweb.com/archives/huddlechat_campfire_rip.php)