Bluetooth won't be "sucking battery". I have BT on 24/7 on my phone and the battery is fine. That's on an old 3GS, the 4S has a lower power BT chip and a bigger battery.
Turn off Bluetooth: If you rarely use a Bluetooth headset or car kit, you can turn off Bluetooth to save power. Go to Settings > General > Bluetooth and set Bluetooth to Off.
So Apple is lying when they say this?
Yeah, but that's not what the OP said, is it? He's talking about some bug he thinks he's discovered.
Sucking power as he describes it isn't something Bluetooth will do - it uses little power compared to the screen, or the wi-fi, or the 3G modem.
Leaving BT on all the time makes next to no difference in battery life. I've tried leaving BT on when not in use, and I've tried turning it off, and my phone still manages two days of use either way. I still take the phone off the charger on day 1, use it all day, leave it that night, use it the next day, and by the evening of the second day put it back on the charger. BT on or off doesn't make any difference.
Obviously if I'm USING BT in the car, then the battery drains faster. But just having it on, not connected to anything doesn't make any measurable difference in my experience.
All I can say is what I have discovered.
this "bug" when I freshly wipe my handset and leave it in a brand new state unused without going into General > Settings and selecting bluetooth off battery lasts between 3-4 hours. I'm getting many many more hours now its in the OFF position.