You won't find it in any site navigation, searching yields almost nothing, and the team at GenerationMP3 admit that they stumbled on it by chance (you can still find it via cached Googlepages, which indicate that it was on the U.K. site's navigation at some point in recent history).
At minimum to keep up Google would need to add Google Chat as part of the browser so that people could chat with their friends while visiting non-Google web pages.
Sullivan argues that "knols"--Google's name for the individual pages in the new content network--will take high spots in Google's search results because people will create more links to pages that have a Google signature.