I have a Zune and its the greatest thing ever. I broke my Ipod 30g video and seriously, it took me a month to build up the kind of scratches an Ipod gets in 3 days. The layouts are nicer with the Zune, video is higher quality, and so is the sound quality. The only negatives are that there are no accesories other than radio transmitters and car chargers at the moment, and I would like to see an alarm clock in the future, but hey.
If you're not planning on getting one soon, then I suggest you wait for next year's Zune to come out. Its supposed to blow the iPod right out of the water.