They are the new ones, the non Pro with the USB on the back, my girlfriend just picked up her 15in today.
She likes it a lot more then my black Pro keyboard, she felt it was to soft and was even a bit worried she would have to buy a new one for her iMac. I guess its just a personal preference though.
edit....
I should add that it doesn't come with a USB extender so if you don't plan on having the keyboard right in front of your iMac you'll probably have to buy that, which was another trip out the store (first was ethernet).......