They sure are

Electricity

Johnnie Ray mentioned

Shows up in Supernatural

Both this song and American Idiot references the Bush Administration via kenning ("Cowboy presidents" and "redneck agenda" respectively)

For me it was that since early onset Alzheimer's is mentioned in two episodes in a row (In Binary it's mentioned to be one of the illnesses that Sergey Ushanka could've suffered from, and in Held in Customs the post-statement portion of the episode it comes out that Vincent Yang had it) it would be revealed that the End was involved somehow. Also once the subject of rituals started playing a larger role I thought that it would turn out that the second law of thermodynamics was the result of a successful End ritual.