I got mine for my son, so I'm happy, but here's the whole story in a nutshell.
Seems that when they thought up this whole idea, Google wanted a really low price, but they only had so many billions to throw at it (they were being cheap). LG was a big loser in the smartphone wars, so they had this production line in the middle of nowhere that wasn't doing anything. Thus, they were willing to live with a small margin just to keep the line going in case they were successful one day.
So, Google threw petty change at it, and reserved this pitiful line, thinking that they'd never sell much. After all, they had Motorola for expensive phones. LG was happy, since they cut off LTE, and it wouldn't cannibalize their top line, which was selling a bit.
Big Surprise! A bajillion people wanted this phone, and they could only churn out a 100K a month, tweaking it to 200K if they didn't allow the workers to pee. Google accused LG, and vice versa.
In order to boost production, Google has now had to move to a real line. This probably means big money down the rabbit hole. They need to boost to a million a month, and LG probably has to cut Optimus production, which was selling because the Nexus was so short. Like I said, big money.
Now Google is about to open the doors again, and if they learned anything, they will have shiploads of them. All heavily subsidized. Get yours while they're hot!
*the above is a fantasy story, based on what I have put together on this. Don't sue me!
Update: It's back! Ships soon.