Yes. However, you probably give up 10-15% of the current iOS market as you can see on that page who are using iOS 5.x. There are also considerations like the

Yes. However, you probably give up 10-15% of the current iOS market as you can see on that page who are using iOS 5.x. There are also considerations like the most active users would be on iOS 6. Also consider iOS 6 is on 300 million+ devices (as of late January 2013).