A visit to http://www.huddlechat.com/ grants the following message:
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)
This was really blown out of proportion. If anyone wants to perpetuate conspiracy theories you've got plenty of ammo with AppEngine. This HubbleChat thing is/was nothing. Cope.