Surprised? Well I totally was and I think many other people were too. I thought this show wasn't going to get backed, but I guess ABC is willing to give a chance to Forever and I'm glad they are.
Someone speculated that the only reason the show got backed is because the network is holding on just in case Castle doesn't get renewed (actors are asking for $1 million per episode). Another said it's because ABC doesn't have any confidence in its midseason lineup. Maybe, it has something to do with no one having done this well at that time slot in 4 years (it goes up against Person of Interest and Chicago Fire both shows I watch as well).
Only ABC knows why they gave it the extra 9 episodes coming to a total of 22 episodes. But I can tell you one thing, this fan is very happy about the news.