It shows up from time to time - I think it has something to do with apps being miscategorized. Every time it shows up, whatever is in there is not a theme. Usually disappears after a bit
The Theme section shows up whenever there's an app in the Theme category. The category an app goes in is controlled by the developer when submitting to App World. Themes and apps are no different to App World so there's no checking to make sure it's really a theme. So basically, blame some developer who didn't understand how to select the right category. Given how high profile the mistake is I'm sure RIM tells them to fix it pretty quickly.
