The problem with putting the light in front of the screen is that there's nothing to protect it. This might not seem such an issue because most screens are sturdy enough to survive basic damage, but in the case of the Nook Glow that's not true.
I can confirm that based on the many times I've dropped one device onto another that screen are fairly sturdy, but it looks like the light layer on new Nook Touch isn't even as sturdy as the (accident prone) E-ink screen right underneath it.
You see, the mark on the screen above isn't from dropping the Nook Glow on the floor. It's not from dropping something sharp onto the Nook Touch, or even keys. No, the weapon in this case was a regular TV remote control which was accidentally dropped from less than a foot above the screen. It left a ding in the light layer which is visible even when the light is turned off. And when the light is on I think it ruins the reading experience.
Now, the blogger at Gizmodo is still saying that the new Nook is worth it, but I disagree.
I can accept that devices break and that you sometimes need to be exceptionally careful, but this is just too much. My devices get more banged up than that just by putting them in my bag. With all the pens, notepads, and other stuff I carry around while on the go I would be lucky not to end up with enough scratches on the screen for an abstract piece of art.
I think we may have celebrated the new Nook Touch a little too soon. That frontlight might be as nearly invisible as glass but it is also much more fragile. The photo above is a good reason not to get the device. Clearly it's only one minor accident away from being a waste of $40.
Update: A couple readers disputed the accuracy of the photo above so I did a little experimenting. I dropped my keys on my Nook Glow from a height of 4 inches. This is the result: