Lumia 920 is still seeing good stock movement in USA. Just some time back all the colors became available at AT&T after Cyan returning in stock. But Red Lumia 920 has got sold out now at AT&T and is listed as “out of stock” . In case you want one you can still head to Amazon or Walmart and buy one at $69.99. But if you want that “Free Wireless charging plate” then may be you have to wait.
Lumia 810 is also doing really well at T-Mobile. It is currently price “Free” in web only pricing by T-Mobile. It is the 6th Best seller device at T-Mobile beating likes of HTC 8X and Galaxy S III.