Besides all market posts and mass comments, the set of new or innovative Voice Features so far are empty. They are just trying to move backwards in time when talking about obsolete and non simple features.
I honestly was expecting much more than a service binded to a real mobile number attached to a formal operator.
In a time that everybody is questioning the meaning of a phone number in the "post email ERA", Google came and released a service based on operator number.
When it might be a short term boom, but as other examples, this might achieve some success not for an innovative concept, but based on Google fame. Google fans probably will use it just to be recognized as early-adopters.
Where is the Interoperability? The Extensibility? The Open Service API? It seems like some basic principles of new Internet where forgotten somewhere under operators shoes.
In short words: "Google Voice does basically what your phone and your operator together always did."
If you are really looking for something that your phone never did before, try Nimbuzz Mobile and feel the real sensation of doing something that your phone never have done before.
Nimbuzz will show you that a "phone number" is the last thing in the world that you need in a full communicator solution.
Nimbuzz uses XMPP and Jingle in order to provide the biggest and feature rich mobile platform ever.