I like my 3G nano better. Its the perfect size. This new 4G is too long with only a slightly bigger screen. A new nano so soon doesn't make much sense. I guess they wanted the Accelerometer (turn the nano for screen portrait or landscape mode like the touch and iPhone) on the nano.
And what's with this "shake" feature to shuffle songs? Nano's were meant for the gym and running (hence the only ipod that can use the Nike + feature) If I'm running or something I don't want my iPod to keep switching songs.
I liked the "fat" one too. It was like a "nano" ipod with the same dimensions. It bugged me that the previous nanos didn't support video and I liked that they fixed that. Now they went back to the stupid vertical design where you hold it sideways to watch videos. Lame.