The display seems to be glued around its perimeter but can still be removed from the plastic framework.

The display assembly weighs in at:

153g for the LCD

193g for the front glass

The glass seems quite thick (~1.18 mm), which is not a huge surprise considering the size of the iPad. Compare that to about 1.02 mm for the iPhone.

The iPad would require thicker glass due to the increased "lever arm" caused by pressing down at the center of the screen. This is analogous to the difficulty of bending a one inch section of a ruler compared to bending the entire twelve inch ruler.