Reports are claiming that the iOS 5.0.2 update has been put on hold because of memory leaks in the code. The update has been said to be a permanent solution to the battery issues and also said to fix bugs on the device and the iCloud service.
The report goes on to say that iPhone 4S users will be able to enjoy up to 10 hours of active usage on their devices. Apple has claimed that the handset should get 200 hours of standby, 8 hours of 3G phone calls, 6 hours of web browsing, 10 hours of video and up to 40 hours of audio.
Apple is still to confirm any of this, so for now we will have to just wait and see.
source - AppleInsider