Then, we made sure to clarify – seeing the “Notify me” page again does not mean that the phone was sold out, instead it was a fail of Google Play to properly display the needed page.
However, not long after it launched, the Nexus 4 has now “officially” sold out in the United States in both its 8GB and 16GB versions. The Nexus 10 32GB has also sold out, but there is still stock of the 16GB Nexus tablet.
You can still buy the Nexus 7 in all its versions including a cellular data one.
While we still don't know how many devices Google Play had in stock, it's clear that there is a lot of excitement about the new Nexus phone and tablet. Hopefully, supply will be able to catch up to that fairly quickly.
source: Google Play Devices