Is Amazon.com Defaced?

Look at the Amazon.com home page -- here's what I saw when I checked in a few minutes ago. This is either a defacement or an upgrade gone horribly wrong! At top is the "view source" and at bottom is what it looks like in my browser.

Ok, I just checked it again. It's back to normal. How weird is that? Has anyone else seen this sort of thing before? Was it a load balancer gone bad?