No product in Apple's recent history has had half as many form factor changes as the iPod Nano, now in it's 8th incarnation. The latest version blends the previous two into something resembling what I would imagine the smallest possible iPhone incarnation. With three rows of two icons there isn't much room on this display, but there is plenty of space for a music player, clock, and Nike+ integration.
Sound quality is the best I've heard on an iPod, but whether a sign of a new DSP chip or just the result of the new ear pods, I can't say. What I can say is that I'm impressed. I sampled music from Gary Clark, jr and various country and classical albums with great results.
If you are in the market for a new iPod, you can't go wrong with this one!