Just yesterday I picked up my N7 where it was sitting on it's Qi charger and noticed a crack going down the left 20% of the screen in portrait mode. I've never dropped my N7 so don't know how it got cracked. I looked into replacing the LCD & digitizer but found it cost about $150 for just the parts. Since I have the 16G model and can replace it for around $200 I feel that's too much so would replace it rather than repair.
Interestingly, the tablet works fine other than everything to the left of the crack being unresponsive. I can use the tablet as is, just needed to re-add icons for 2 apps that were to the left of the crack on my Home screen. I'll probably run into other issues later. For instance, the icons for apps in the app drawer that are on the left will be a problem.