I'll be updating this shortly, but just wanted to let folks know that the Nexus 4 and 7 are up for sale on the Play Store now. However, good luck getting past the server errors. I'm still trying to actually buy the items in my cart.
Update: 12:24pm EST
At least from here, the 8 and 16GB phones are now showing as "Coming soon" again. If you can even get the play store to load. It's slow, buggy, and links often redirect to the home page. The Nexus 10 appears to be in stock, but that's not on my wish list for the day. This appears to be an even bigger e-commerce fail than usual for Google.
Update: 12:33pm EST
The Play Store is such a disaster that it actually seems to be crashing Chrome. Could be coincidence, but I don't think so. Users are reporting repeated boots of items from their carts and are unable to buy phones or accessories.
Update: 12:38pm EST
The Play Store seems to be stablizing, but still no luck on buying a phone. I don't want to be notified. I want to buy something. If Apple can make this work for much higher demand, shouldn't Google, of all companies, be able to scale an online store?
Update: 12:50pm EST
Wait, what was that?! In stock again! No, wait, the Nexus was just booted from my cart and is back to "Coming Soon." Nice.
And 2 minutes later, in stock again, clicked Purchase, and another error.
Update: 1:06pm EST
While the Nexus 10 tablet is showing In Stock, attempts to add it a shopping cart end in a server error. Looks like I could buy a Chromebook if I wanted another one, but reports are coming in of failures for the new Chromebooks at the end of the purchase process (thanks for @SJVN for that update).
Update: 1:47pm EST
Nada. Nothing. Zilch. Zippo. A few moments of hope when the Nexus 4 showed as available for purchase, only to be dashed against the rocks when the transaction failed. And now, many refreshes and several cache clearings later, it's still coming soon. I'm no longer holding my breath. For those of you who managed to snag a phone today, share your experiences in the talkbacks. I'll update again if anything changes.
Update: 1:54pm EST
CNET is reporting that most of this refreshing was for naught. The Nexus 4 sold out within moments of going live in the US Play Store. Thank you, Google, for your clear messages and transparency. And for doing such an awesome job of keeping the Play Store running smoothly under heavy load. Glad I didn't cancel my Verizon service just yet.