I ordered a spare "current" design keyboard on the 11th (july) because I wanted a spare (it arrived a few days later) because I thought I might be in two minds about the possible new iMac keyboard.
I have to say I'm glad I did, cost these pics (after a couple of days reflection) are ugly, I cant see them being better to use ergonomically, than the Current "scooped out key" design. I think from an engineering point the placement of the USB socket(s) is very clever, but from a user perspective its going to mean cables comming out of the side of the keyboard, never mind USB thumb drive or Logic dongles! UGLY UGLY design choice IMO. as with the current design at least eveything is out the back, and if you have a keyboard shelf in your desk they are hidden.
It LOOKS great as a piece of concept, but falls down on a few practical use points.
I think its definitely a prototype and definitely from Apple, which may point to the reason for the lack of the APPLE key? . I also think the reason for these getting out is to source a leak as said above.
I plan on getting a new iMac as soon as they get a healthy update and if this keyboard is included they I will certianly give it a few weeks trial, but to be honest if it remains as seen so far, it will get passed along to someone else.
There are now, of course, some interesting ideas going round my head about what the new iMac will look like

bring it on already!!