It sounds a big news “Google unveiled a Gmail phone call service for Windows, Mac, and Linux.” This is half-baked, at least this is not working for firefox on fedora. After waiting for many days, it seems rpm for fedora was available. Howver, after the rpm installed, the gmail interface still shows lack of the proper plugin
Just checked out, with the latest release on plugin, it seems working.
After installed googletalk plugin for windows and linux firefox, the windoz sibling behaviours well even both linux and windoz firefox showed this plugin installed.