Surface did get picked up for additional episodes in the fall, but not, as it turned out, for a full season of 22 episodes. If my math is correct, if there are only four more episodes before the finale (making way for the Olympics in February), that will take the show to only 15 or so hours in its first season. My understanding is that
this reduced order has to do with budget-cutting at NBC in a year of steep ratings and economic decline, and also because the Olympics and mid-season inventory have reduced the need for new episodes. But it's also just as likely a sign that the network is cutting its losses with this show. (The Book of Daniel is another show caught in the crunch. It went from an initial order of 13 episodes to the pilot plus seven.)
It's too early to know if Surface will be renewed. I wouldn't count on it, but we won't know for sure until we see how NBC fares during the post-Olympics mid-season and with its development crop for next fall.