Music is, of course, a deeply personal experience. But far more instructive of the human condition than that, music is all about sharing.
Ever since our species learned to communicate musically, we have been sharing music- in our celebratory and sacred rituals, to listening parties, through the "you got to come down to the club and hear this great band" invites many of us still extend to our friends and partners.
And if you drive by your city's concert hall tonight, you'll note that there are thousands of people inside. Most are either in couples or small groups-where one in that couple or group told the other(s) about this act, or this concert appearance.
Zune has a wireless-enabled, player-to-player sharing feature that, um, iPod does not.
Here's how it works. You get within transmission range of another Zune user. This feature allows you to send certain tracks to that user. They will be able to play that track up to three times in three days. They won't be able to forward this music, but the restrictiveness of wireless-enabled music sharing via Zune is not the point.
My point is that with enabling of this feature right out of the box (literally as well as figuratively), Microsoft understands that as species, we love to share our music -not necessarily by telling our friends to download a track from an online store because we know they will love it, but by furnishing them the opportunity to try it out for themselves.
And since you are going to already be around this person when you forward them the track you are so enthusiastic about, the wireless feature enables a type of shared musical experience that iPod doesn't offer yet.