Not to hijack this rant, but that's one of the problems with Google Talk: words have meanings. For instance:
* talk
* voice
* chat
See how someone might get a little confused by what "Google Talk" is? They've got a branding problem with the product, because many people still don't know what it is (as a product). Remember, we're talking about a population who probably, by and large, just thinks that a pop-up with a friend sending them a message in their email is just another email interface.
Now ask yourselves, do you think "What do you mean you've got to put this @jabber.org email address at the end of your hangout to talk?" would go over well? I've heard people (younger people, granted) communicate with each other and say "what's your gmail address?" and they just share the prefix in return. Many of these people don't seem to realize there is anything out there aside from gmail for mail, or that gmail is in no way exclusive. For younger people, it's all there has been for as long as they remember. (People who were 8 when Google came out are now 18...)