Wired: Early reports from iPhone 4S owners who have installed the iOS 5.0.1 update suggest that the new release fixes earlier battery problems for most people. “Frankly the difference is nothing short of amazing,” said iPhone owner Donald Kuntzman. “To go almost an entire day without a change in the meter reading seems unbelievable. Where before I could almost watch the battery drain, now it doesn’t move at all.”
Others say that instead of their iPhone's losing 15 percent of battery life per hour, they now lose 4 to 5 percent. However, a few unlucky users say the update hasn't fixed the problem at all.