If you really use the iPod I would wait since some users are having some problems with iOS 6. However, in actuality I expect that only a small % are having problems. Users only post here with problems.
A lot of stuff looks better and there is Passbook. There's not much more to it than that. There are a lot of little things that are changed, like the settings icon etc. I haven't updated as a lot of people have had problems with it and I am not making the same mistake I made last year with iOS 5.