Thom Holbrook, who runs the encyclopedia of TV crossovers (His link is the top one at the left, Team Toobworld - that's how important it is!), asked this on Facebook tonight (11/11/12):
"Did I just see 'The Middle' crossover with 'Pawn Stars'???"
Technically, 'Pawn Stars' already existed in Earth Prime-Time just by being broadcast. But it's always better when there's an actual connection made to another show of fictional content. 'Jeopardy' on 'Cheers', 'Wheel Of Fortune' on 'L.A. Law', 'American Gladiators' on 'Family Matters', 'Big Brother' on 'Yes, Dear' etc. - that sort of thing.
So this sub-plot on 'The Middle' gives 'Pawn Stars' Toobworld street cred. And it puts Rick Harrison just one credit away from eligibility for the TV Crossover Hall of Fame.
Thanks for bringing this to my attention, Thom!