I think that Microsoft's mp3 player (Zune) has no reason to exist.
Why? There is just a huge amount of better players: first of all the iPod and then Creative's products.
What's wrong with Zune:
1. Name: sounds like Zen (a Creative's mp3 player) plus iTunes (Apple's software to handle music)
2. Who made it: Microsoft didn't make it; Microsoft bought a truly unsuccessful product by Toshiba...
3. Size and weight: Zune (30GB) it's larger, thicker, taller and more heavy than the 80GB iPod!!! Why the hell would you buy it?! And it's only 30GB.
4. Battery life: its battery life is much shorter than iPod's
5. Wireless: you can't use Zune wireless to sync it with a PC, altought you can share music: you only have to wait hourse before it actually finishes up
6. Quality: iPod's quality is good (sound quality is very very good) while Zune screen cracks from battery pressure
7a. Software: Microsoft's software to handle the Zune is not even as easy as iTunes and its Music Store doesn't have as many song as the iTunes Store (which also has podcasts, videos, audio-books, ...)
7b. Software again: Zune cannot be used with Windows Media Player 11 (!!!) and wasn't, in its first release, compatible with Microsof't own Windows Vista!
7c. Software once again: what if you want to buy a song from the Zune Marketplace? I gues you're pretty sure you can't use your credit (or debit) card... well you can't! You have to use Microsoft's points! ...And you can't buy only one song you have to spend al least 5 dollars!
8. Storage: Zune only comes in a 30GB version while the iPod has a 80GB hard-drive; moreover Zune cannot be used as an external hard disk.
9. Money: Zune costs as much as a 30GB iPod but be aware that a small but consistent amount of the money you paid goes directly to discographers! You're right: Microsoft thinks you are a thief. So bad!
10. Availability: it's not even available in Europe...
11. Copycat: the Zune has a sort of button which really really looks like an iPod's click-wheel. But that's not all: it has copied the ugly and big form factor of the Archos line!
12. Color: Brown?!? OMG!
Conclusion: if you don't like the iPod don't hurt yourself buying a Zune, buy a Creative player!