The battery life on my iPod has been really good since I got it - longer than the 4th Gen. which wasn't that old.
I experimented and got 44 hours of audio last week playing a mix of aac, mp3 and ALAC files, not using the screen much. That's compared with the 40 hours which Apple says.
Typically I use the Touch for a mixture of music, 2 hours of ereading and a little browsing/playing with other apps each day. I find myself charging it every couple of days or so which is usually when I want to sync it with my PC, and when it's down to around 50% or so.