I'm wondering if they're going to offer plausible, modern-day explanation for why everyone calls him "Jughead."
It's possible they'll use the same one from the recent Mark Waid-Fiona Staples comics:
http://comicsalliance.com/jughead-jones-archie-2-preview/
As for the, err, original origin, I found this Snopes message board discussion, and apparently it's an early 20th-century slang term for a fool or a dumb, lazy person, perhaps derived from a slang term for a mule. It might also be a reference to the comic-book character's narrow head and protruding ears, like the handles on a jug.
Not an original observation, but it's been pointed out elsewhere that the pop-culture references on this show are oddly retro. In the first two eps alone, these 21st-century teenagers have name-dropped Truman Capote, "Our Town" by Thornton Wilder, the Joan Crawford version of "Mildred Pierce," AND Montgomery Clift, "pre-accident."
Mind you, I've barely set foot in a high school since the seventies, but are modern teens really that culturally literate when it comes to vintage plays and movies? My impression is that most of them are only barely aware of any movie or TV show made before 1975 or later . . . .
Isn't it mostly Veronica who's dropping those references, though? I think the point is that she's making a lot of esoteric film references the other kids don't get, to highlight that she's from a different world and social stratum.