We're all users like yourself so we would have no way of knowing what Apple is planning until the announce it.
Battery issues are commonly reported after every iOS update.
Basic troubleshooting from the User's Guide is reset, restart, restore (first from backup then as new). Try each of these in order until the issue is resolved.
I'm having the same issue, but without having upgraded to iOS 6.1 - it just started out of the blue last night.
- It suddenly heated up, I turned it off. Battery at 87%
- After maybe 45 minutes, I turned it on again. Battery at 45%. It would not charge at this point.
- I tried MANY things, including turning off WiFi, mobile data, location services, Gmail sync (though not Exchange sync, which had given no problems before. I'd recently changed some Gmail settings, so I reverted them).
- I tried to restore, but my crappy internet was unable to download the iOS 6.1 file.
- I looked it up on the internet and performed a hard reset, after which the phone began to charge, to my delight.
- I charged it to nearly full (92%) then lay in bed using Twitter and iBooks for some time, after which battery was at 65%.
- After sleeping for around 7 hours, the battery lies dead. Attempts to charge it (both from the wall adapter, which is a standard India 220V charger, and from my laptop) are making it flash the Apple logo for around 4 seconds before the screen turns off; this repeats ad infinitum.
What do? The nearest Apple Store is three hours away and I have exams on; can't get away before Saturday at the earliest, so I'd like to have some use out of the phone in the near future.