I just recently got the iPod Nano, and I have to say that it's great. The design is VERY sleek and hawt. The quality of the music is very good, and the LCD screen is fun to stare at while listening to some tunes. I love the way things are organized on it, as well. There are plenty of extras, like games and clocks, etc., which are kinda fun.
The only problems I have are that the ear pieces are, for some reason, a tad uncomfortable. I'm either not wearing them right (I'm almost sure I am), I have mis-shapen ears (I hope I don't ), or they're just shaped kind of weird.
The other problem is the space. Although it's not much of a problem for me, and I have the 2gb one, the really avid music listeners pretty much won't be able to own this or they'd run out of space quickly. The thing I'm worried about is that I'd eventually run out of room over time...but hopefully they'll have a much larger one to purchase by then.
Overall, I'd rate this MP3 player about an 8.5/10.