The Zune will be compatible with Microsoft's own music store and has a wireless music-sharing feature (with lots of restrictions). It'll nag you to buy stuff you don't own. But if Micr$oft kit is your thing....
I'm a great fan of Creative kit. User interface, alright but not quite as good as Apple. Flexibility, build quality, reliability and sound quality very good.
The radio-recording quality is not so good though, ok for news maybe. So, when I lost it in the latest firmware upgrade, I didn't miss it. Who records off radio these days?