Fortunately, the glass is separate from the casing. In fact, nothing but the iPod's internals hold the glass in place on the casing.
The front of the glass is curved to match the front of the iPod. The glass is about .7 mm thick on the edges, and 1.7 mm thick in the middle.
The new LCD is actually almost exactly the same size as the 3rd Gen Nano LCD. The only difference is that instead of a resolution of 320x240, you now get 240x320.