Tonight, new episodes of CSI and Supernatural will air.
Some things to keep in mind:
1) Greg and Sam both went to Stanford.
2) We know, canonically, that Dean and Sam tracked the demon to Vegas at some point.
3) In tonight's episode of CSI, we know that
Greg is attacked by what appears to be a gang of vampires, complete with luminous eyes and a pack mindset. I'm sure they'll turn out to be hip, blood-drinking costume fanatics and not creatures of the night, but... In Supernatural, we know that
vampires are real, and they have a mad-on for Dean and Sam. They mate for life, and they never forget a scent.
Really, now that I've laid it all out so neatly, nobody has an excuse not to write it.
4) As a slightly CSI-related aside, did anyone notice a correlation between Nick's part in Gum Drops and
the psychic cop's part in finding the little girl in the wall? Coming to a grisly murder scene, child's missing, he's sure she's alive somewhere, he's the only one who's able to find her, they have the beginnings of a special connection after that? Factor in that "your third eye is wide open" interlude with Sage in Gum Drops, the creepy whispered voice-over, the way Nick acted like he was hearing things throughout the episode, and you have crazy crossover and AU potential.