I have to agree it would be marginal from my experience with my iTouch.
Both Wifi and Bluetooth go to sleep after a while on standby, unless you have the music app running.
And geo services must sleep after a while throughout use where an app isn't calling for it. You can see this because sometimes and app will ask you if it can use geo and other times it won't. I've noticed that the times it asks on maps it takes a bit longer to lock.
What does kill it though is turning it on and off installing apps, which after a bad install experience this weekend I will MAKE SURE I do in future!