My uncle's actually on the software development team for this, which consists of only 20 or so engineers. Still, that doesn't persuade me to part with my 80 gig video iPod.
I think its biggest advantage over the iPod is that it's wi-fi capable. I'm sure this was considered by Apple, but they probably rejected it due to the added bulkiness. iPods are slim and fashionable. Microsoft seems to be taking a different approach and developing the hardware first, then working on making it smaller, thinner, with a bigger screen, etc. The fact that it has wi-fi is cool and all, but I don't really see any practical use for it at the moment. Maybe somewhere down the line so you can wirelessly connect to your stereo receiver or TV or use it as a mobile browser or something. But for now, all you can do is share songs with another Zune user for a limited amount of time.
The Zune network's a cool idea, but again, it's going to need some more development before it becomes favourable. One of its restrictions is that the songs aren't in mp3 format, so you can't copy them or burn them to a CD. It's the right approach when it comes to downloading music, but I think they're going about it wrong.
By the way, apparently "Zune" is a euphemism for genitalia among French-speaking Quebecers.
It's also especially vulgar in Hebrew. My uncle got a good laugh out of that.