I think they should make a timeline pin by decade. The theme would be based on current events and music of the decade.
1960's-vietman war, Kennedy assinated, Alfred Hitchcock's Psycho, escape from Alcatraz, Woodstock, etc... and some great Bob Dylan, Beatles, (right!!), Eric Clapton, Pink Floyd, Cream. I am showing my age but could list some great music from the 60's.
The next game would be the 1970's, MASH, US pulls out of Vietnam, Elvis is dead!!(a few vicoden, codeine and valium drop into the coin return slot) , London bridge brought to US, (London bridge on the playfield), some really cool psychodelic music, doors, Jimi Hendrix, Styx, even some disco with a small disco ball)
You get the idea, each game a different decade, up to 2000.
1990 could start out with the Iraq invasion, looking for weapons of mass destruction and the game does a ball search forever.... WACO, OJ Simpson murders his wife,(a bloody glove grabs the ball like Thing on TAF), Lorena Bobbit,(a severed pecker pops out of the playfield as a ball stop), (please don't take the next one as racist) Nelson Mandela free, (black pinball scores extra points during Mandella mode) , Titanic Movie, (sinking titanic on the playfield). etc........ But no Brittny Spears, PLEASE!!
Bet getting rights from all the different artists would be almost impossible though.