I have been a proud and loyal Apple iPod user since they first came on the scene. I didn't really have a problem with their product and I wasn't looking for a replacement. My curiousity and love of electronic gadgets got the best of me and I bought the Microsoft Zune. It is great.
The device is roughly the size of a deck of playing cards. It has a large screen and controls similar to that of an iPod. I mainly use the device to listen to music and watch videos. when playing videos, the image is displayed lengthwise to optimize the screen size, so the device is held sideways to view it properly. I have copied a few of my DVD's and placed them on the device.
The player also has the ability to play radio and podcasts, though I haven't used those options yet.
The real downside for me is the software needed to get your music and movie files onto the player. It took me half a day to get everything successfully loaded. I've heard similar complaints from others, so it doesn't look like it was just "user error" on my part. However, once everything was loaded, I couldn't be happier with the device.