As @Eric mentioned in his update, the scrollViewWillEndDragging delegate now takes an UnsafePointer. To update the Unsafe pointer, you just have to access the memory property.
func scrollViewWillEndDragging(scrollView: UIScrollView!, withVelocity velocity: CGPoint, targetContentOffset: UnsafePointer<CGPoint>) {
targetContentOffset.memory.y = x + 1
}
*Tested and working with Swift Beta 4.
UPDATED FOR BETA 5
Swift Beta 5 scroll view delegate uses an UnsafeMutablePointer instead of UnSafePointer
func scrollViewWillEndDragging(scrollView: UIScrollView!, withVelocity velocity: CGPoint, targetContentOffset: UnsafeMutablePointer<CGPoint>) {
targetContentOffset.memory.y = x+ 1
}