Update 2: The Nexus 4 8GB model appears to be back in stock once again on the US Play Store, with a shipping estimate of 2-3 weeks.
Update: Apparently, some people are still seeing the 8GB version as still shipping in 2-3 weeks. However, if you actually attempt to place an order, you'll get the "An error occurred while processing your purchase. Please try again later" message. So, it's probably out of stock everywhere in the US, the change may just not have propagated across the internet quite yet.
Well, it took a whole nine days this time, but after returning to availability in the US Play Store on January 29th, late last night the Nexus 4 8GB edition went out of stock yet again. Black bumper cases remain unavailable as well.
Unlike the previous supply calamity, Google didn't allow shipping dates to reach into the stratosphere before pulling the plug on orders: the estimate ship time slipped to 2-3 weeks, and thereafter the "Temporarily Out Of Stock" message appeared. The 16GB model has also reached the 2-3 week mark, so it's possibly that it may become unavailable again shortly, as well. While mid-February is supposed to mark the end of 'supply constraints,' if you're on the fence about ordering that 16GB Nexus 4, now may be the time to do it.