Ended up ordering 4 phones instead of 2 because of the whole google system getting messed up on the initial day. I ended up selling the two extra to friends at cost of course. We've had the phones for about a month now and the predicament doesn't look good:
Phone 1: While wearing dress pants at work, I stood up, put phone in my back pocket with nothing else in it, walked to a meeting two floors down, pulled out the phone and felt a little sharp pain on my finger. On that short trip with nothing touching it and nothing hitting it, the back glass broke around the top around the camera and down about an inch in an arch and back up on the other side. There was no case on the phone, but then again, nothing was in the lose back pocket and nothing hit it. I've had an iPhone 2g, Nexus One, and a Nexus S, and this is something I've always done with all those phones over the many years without breaks. No cases on them ever.
Phone 2: Since phone 1 was putting glass into my hand, I was going to steal the case from phone 2, which was my wife's, that had been on it since the day we took the phone out of the box. The phone was never dropped, but she does put it in her purse. When I took the case off of her phone, I found the back of her phone was cracked. Again, she's had the iPhone 2g and the Nexus S, in her case both have had cases on them, but no issues.
Phone 3: My friend dropped it while he was getting it out of the car dock and the phone landed on the dash below, and the front glass cracked and spidered for the entire bottom. To find out even more, it had actually landed on the side at an angle. This one is easily debatable and could be user blamed. Seriously though, four years of having other phones since Nexus 1, just as clumsy with others, but this one he said cracked unbelievably easy. Might have just hit a sweet spot. Who knows. He did mention that while looking at where it hit, on the sides of the phone, the glass actually has corners in the cut that aren't protected by the frame and it landed on the glass corner and that's what did it he thinks. He didn't have a case on it, but again, he's never had a case on any of his smart phones in the last five years and this is the first one that broke.
Phone 4: Actually still not broken.
I'm just feeling that something is up a bit since 75% of the phones we have are broke within the first month, with people that have had smart phones for years before without issues. If you get a Nexus 4, get a case that covers those exposed glass sides at the least.