If you use Google Voice, or simply make the occasional outgoing call via Gmail, Google's got some great news for you. The service is going to continue to be free throughout 2013 for users in the U.S. and Canada! International callers will still have the same rates applied. In short, nothing is really changing, and that's a good thing.
When Google first introduced the ability to make phone calls in Gmail, it said the service would be free through at least the end of 2010.