I've got a Zune. It's basically Microsoft's MP3/video player thing. A lot like the iPod. Overall, both iPod and Zune are grossly overpriced and I would never EVER pay for one. Got my Zune for free.
I've never gotten a Zune pass..... because I don't need one.
As for differences, I've got the Zune 30 - the original Zune release. Unlike the original 30GB iPod, this thing's got a radio tuner AND Wi-Fi. I've even got a few games on it, now. When you compare the 30GB iPod with the Zune, the features for the Zune most definitely win. However, since then, iPod has come out with various upgraded models that put it on top.
As I type this, my Zune is on the docking station and playing.