If you're old enough, you may remember seeing the original run of Cosmos, a thirteen episode love letter to the universe, from Carl Sagan. Sagan was hardly the first popular physicist, or popularizer of physics. But he was certainly one of the most successful. The only other success of this scale that I can think of is James Burke, who is more of a polymath than a physicist, and doesn't limit himself to cosmic scale questions. Burke is still alive and weaving that web.
Nobody has arisen to claim the throne, though there are a host of adequate popularizers out there. I'm now placing bets, however. In the past several weeks I've seen at least two articles referring to a physicist who has begun hosting documentaries about high-energy physics. Thus far these films have been limited to physicists and their conferences, but I'm seeing a growth in visibility which leads me to believe that Maria Spiropolu is aiming for the brass ring. Does she have what it takes? I don't know. It all depends on whether she has screen presence, and a recognizable style. Can you say "billions and billions"?