This seems quite extraordinary to me. It's now been two and a half weeks during which it's simply not possible to buy an iMac, old or new, on the Apple website. And it's not even allowing us to order it yet, never mind deliver.
I don't remember any other time previously when there was this period of total limbo on the Mac side. And I don't see what the problem is - all the rumours previously were about production difficulties with large retina displays, but this iMac isn't even retina, so what's the problem?