You interpreted incorrectly. In no way is that them saying that they will air every episode. That is them saying they've planned 15 episodes and feel hopeful that all will air. In NO WAY is that a guarantee.
Anyway, the overnight ratings rebounded nicely on 2/18:
It was up 55% over Alcatraz the same week last year.
At this point, I feel comfortable we'll see all the episodes. As I noted in the ratings thread it appears that the demo audience is holding at about 85% of the premier and Fox simply doesn't care about the fact that the 50+ audience is down a third. It's demo last night was higher than "Bones."
I just don't see Fox cancelling this show even if episodes 9-12 are way down. An order for a second season will depend on how episodes 9-14 do, but I'm not worrying about that.