Google employees use Google's services to get feedback from users and to share the latest updates: Blogger, Google Groups, YouTube, Google Moderator, Google Spreadsheets and more. Some important benefits are that they test Google's services, find bugs and they're more likely to improve the services. Often, Google's employees are regular users and they'll see the same bugs and limitations as any other Google user.
Stefan Küng clicked on a link from Google Talk Labs Edition FAQ which was supposed to send him to the Google Talk Labs Edition Group. Unfortunately, Google's own group has been removed because it violated Google's Terms Of Service.