I have found a trick that let me order a Nexus 4 16GB just moments ago (around 1:10pm EST). I plan to use the device for reviews of upcoming “Holo” apps.
Here’s how it works:
1) Go to https://play.google.com/store/devices/details?id=nexus48gb 2) Where you see the option to “Choose another Nexus 4″ click between the 16GB and 8GB versions.
After doing this a couple of times I was able to “Add to Cart” both the 8GB and 16GB versions (I only went ahead and ordered the 16GB).
Trick is still working this moment (1:15pm).
Update: You may see an error in the cart when you try to check out, just go back and retry the process above (after three failed attempts we got through, and just received our confirmation email).
Also, for those wondering, we were able to checkout using Chrome (but IE8 also appeared to work as well) and I can only confirm that this works in the US.