The Kindle edition is back. Amazon PR person Brittany Turner wrote, "Wanted to let you know that this book is now available in the Kindle Store." Ms Turner didn't offer any further explanation.
Presumably, it was a dumb mistake to begin with, but one that couldn't be corrected until there was enough publicity to get senior people to look in on the issue.
I write books. My latest is a YA science fiction novel called Homeland (it's the sequel to Little Brother). More books: Rapture of the Nerds (a novel, with Charlie Stross); With a Little Help (short stories); and The Great Big Beautiful Tomorrow (novella and nonfic). I speak all over the place and I tweet and tumble, too.