You have to download a little google-extension/plugin, but you had to do that for Google’s other hyped-one-day-project-gone-the-next, Lively. I just hate restarting my browser.
Google is pretty clever to include into Gmail. They made chat for that reason and then added the voice to the chat and now the video to it. Gmail is slowly becoming the origin for many Google-projects.
I doubt they’ll even update the Google Talk Client. The Labs edition totally fails (how can you leave out file transfer?) and the regular client is hardly updated. I use the regular client much more than I use the online chat. The only reason I use the online version is for group chat. All (aim, msn, yim) other services have group chats for their client version. (Of course, their online counter parts don’t offer very much.)
At the very least, they did a global release of this with Google Apps included. One thing is odd though. Where were the beta testers?