I notice that the Trending Content sidebar on the home page is dominated (3/5) by threads from 2001, nearly some of the earliest threads on the site. None of these have been necroed at all, last post was 2001 for all three. Definitely something up with this.
It seems like it's almost failing to cache new content and when the current cached items fall off it just defaults to these ancient threads. This morning another of the current threads was replaced by a thread from April 13 2001, leaving only 1/5 threads as something relevant.