Becoming a wireless carrier would not play to Google's strengths. Google generally succeeds in markets where they can leverage smart engineers to serve hundreds of millions of users. They tend to fail in markets which require human interaction or physical presence.
Google does, however, have strategic interest in keeping the mobile internet market as competitive as possible. So I would expect them to chip away at the carriers indirectly, much as they use Chrome to chip away at the IE hegemony, or as they use Android to chip away at the iOS.
Google does, however, have strategic interest in keeping the mobile internet market as competitive as possible. So I would expect them to chip away at the carriers indirectly, much as they use Chrome to chip away at the IE hegemony, or as they use Android to chip away at the iOS.