Emmert is apparently looking to Champions Online, another MMO that just shifted from subscription-based to free-to-play, as a guinea-pig of sorts. "We're not sold one way or the other with Star Trek yet," he said. "If people want Star Trek to go free-to-play then get in and play Champions and help make it a great success, because that would send a strong message."
Champions Online's free-to-play model splits players into groups of subscribers and free-to-players. The free-to-play members don't have access to all of the bells and whistles that subscribers receive, but can still play most of the content for free, with á la carte purchasing options also available.
When asked to comment on the ultimate likelihood of Star Trek Online going free-to-play, Emmert said, "If we did Turbine's level of success that would certainly merit the discussion," before qualifying, "There are more people than just I on that decision and I can't begin to say it would be an automatic 'Yes, we'd do it.'"