This was just announced a few days ago:
"AMD will soon deliver open graphics drivers, said Henri Richard just a few minutes ago, and the audience at the opening keynote of the Red Hat Summit broke into applause and cheers. Richard, AMD’s executive vice president of sales and marketing, promised: "I'm here to commit to you that it’s going to get done." He also promised that AMD is "going to be very proactive in changing way we interface with the Linux community."
It looks like Nvidia's is now the only
closed source driver from a major manufacturer. From here