I think you hit the nail on the head!
This seems to be the cause of huge cell data usage as well..,.. probably all that cell data usage is draining the battery.
Before getting my 4s AT&T data usage averaged between 350MB to 500MB per month. This was without any kind of push/fetch email content or other background stuff and wifi disabled 100% of the time.
Typical usage was web based email, surfing and about 300 mintues of phone time per month, no streaming or video (sometimes I would update or download an app if it were small enough for loading by cell.
When I got my 4s, I kept all the pushing /fetching shut off on evertything and enabled wifi, I did have the icloud enabled for the findmy iphone and for backing up contacts and calendar. oh, I also had disabled the ping and all the system services in the locations menu.
My billing cycle begins on the 2nd of the month, on the Nov 10 I checked my usage on AT&T and it was 995MB with only 7 days usage using wifi 100% of the time as I work from home and didn't surf or use data the few times the house. This is like an 8X increase in data at the same time I started using wifi. Data should have gone down from my monthly average as I went changed over to wifi.
In fact in a couple of 12 hour periods it reported nearly 100MB data.
During this time I didn't consider my battery usage as being too bad as it would drain at about a rate 16-20% before updating to 5.01 and then a little better at ~14-16% per hour after 5.01 (these percentages are while using the phone, not standby) in standby maybe a percent every 3 hours. At night the phone is plugged in charging.
After seeing this huge data use, I disabled all icloud backup as well as changed. Since I've done this the data usage (since I'm on wifi) has been less than 500k / day and battery lasted longer too.
The past 2 days I've also shut off all cellular data (since I'm home on wifi) and in this time cell data usage is zero as it should be, what surprised me was that for the past two days, the battery has averaged a 10% drop for every hour of usage (not standby).
I do think there is a bug in how icloud uses data and how often it backs up or some other bug that is allowing huge amounts of data to get sent somewhere.
Oh, in case anyone asks, I always delete the background tasks so none of them stay running or suspended.