Personally, you'll be plenty happy with either the iPod or the Zen Touch. I used to not be a fan of the iPod, but after using one for a few months, I grew to like it a lot. The only thing I missed from my Zen Touch that I had been using mostly before it, is the battery life (which never was a problem for me with the iPod).
Not to say anything bad about the iPod, as its been my favorite MP3 player, and I've used plenty of them (Zen Touch extensively for one), but I was positively astounded by what I heard someone in my marketing class say.
They said that they did not know of a single other MP3 player that could hold as many songs or have as many features as the iPod. The instructor, while not exactly knowledgable on the vast amount of players out there knew enough that it wasn't true and he was trying to say in a nice way that the person didn't know much (seriously, unless all you go to is the Apple Store, how could you not know of other players that offer as much storage and features?). I would've corrected them, but I gave up talking in that class after discussing some other things and the absurdity that the people would say (they're the typical brainwashed consumer that now hates Wal-Mart but still shops there, thinks Apple is the only MP3 player because it looks good, would say BOSE makes excellent products, among the many other trends in consumer stupidity).