Judging from other statements made by Mongoose, Amazon is in a weird place at the moment: "trade" shops are getting the book right now, but the large book chains won't get it for another few weeks. So, Amazon can list the "affiliated sellers" that have it, so it's technically available, but Amazon themselves don't have it and won't for a while.
And Alex - thanks for the tip on Time Machine. I was able to get the single copy they got this week held for me.