The new Zune's just slightly bigger than the iPod classic, measuring about 5mm taler and 2mm thicker. It's also slightly thinner than the 30GB Zune, with 3mm height, 1mm width and 2mm depth separating the two. When you're comparing 80GB to 80GB, the size different doesn't' seem like it's going to be enough to make any sort of meaningful difference.
But when you're comparing the Flash Zune vs. the iPod Nano, things get a little tricky. The Nano's now fat, which means it's shorter but wider than the Zune, so it's kind of weird. But if you look at the iPod Nano 2G vs. the new Flash Zunes, it's almost exactly the same size. However, Microsoft's player still comes up a little fatter, wider, and thicker. [Sizeasy]