Amazon has put up the hardcover. More or less. They have a page, and you can order, but they list it as “Temporarily out of stock.” Still, I’m sure if you do order they’ll ship in a couple of days when they finish sorting out their internal business.
They also haven’t totally connected the product to the Kindle and Paperback editions. I find it interesting how their site puts things together piecemeal. The must have various background jobs that massage the data and not all of them run together on the same schedule. I.e. the “book importer” job puts books in but the “book merger” job later connects various editions together.