It’s apparently not live yet, or at least it’s not visible to all users, but Amazon seems to be preparing to release a new version of the site.
I saw the new page briefly yesterday afternoon. After taking a few moments to appreciate the category menu and the realignment of the header, I clicked on the “We’ve been remodeling” link in the top-right corner. I was taken to a page describing the redesign, but with the old header and menu. Sure enough, when I went back to the homepage I was greeted by the old design.
The new look seems like a big improvement and I’ll be anxious to check it out when it goes live.