Since writing about our upgrade experiences, I have had reports from several friends of fast battery drain with the new operating system. I have also experienced this: It is now 11 am and my battery level has fallen to 54 percent only two hours after disconnection from the charger. This is unusual, bearing in mind that the phone is only two months old and the battery was performing well up to yesterday. It’s early days and I need to investigate settings but I suspect there is a general problem.
This article in PocketLint includes a number of useful tips for maximising battery life.