I am definitely seeing a decrease in battery life on my iPhone 4S with the new iOS updates. Long story short, I had the 16 GB, now I have the 32 GB. Both had an exceptional battery life in the beginning, then slowly began to decline with the iOS 5.0 update, then worse with the 5.0.1. For example, I began using my iPhone around 1:00 PM today & the battery life is currently at 19%, approximately 9 1/2 hours later. When I first purchased my iPhone 4S back in October, I was really impressed with the battery life, especially when compared to my old android phone, which would never last throughout the day. Now it seems that the iPhone is slowly headed that way as well. I do have several apps installed, which is why I had to trade my 16 gb in for a 32 gb, which I suppose could contribute to the battery situation. On the android, there was an app called task killer that would shut down all apps running in the background. I'm not yet familiar with how the iPhone works in regards to apps and battery life. I hope they get this matter resolved. In the meantime, I will continue to charge my battery in the evening when it inevitably shows the battery life as under 20%.