Steven Spielberg dies and goes up to heaven.  St. Peter runs to meet him at the gate.  
“Thank you-know-who you’re here. We’re doing a movie and we need you to direct.”
Spielberg mentions that he just died and would like to get used to being dead before he starts working again.
“But we got a brand new screen play by Bill Shakespeare.  First thing he’s written in hundreds of years.” St. Peter says.
Spielberg’s eye brows go up.
“AND Michelangelo is doing sets and artistic design, and we have Bach and Chopin collaborating on a new score.”
“That’s fantastic.” Spielberg says, obviously getting excited.  “Shakespeare, Michelangelo, Bach, and Chopin in one project.  Who is starring?”
St. Peter looks down at the cloud he’s standing on, and stammers, “Well, we got one problem.  See, God has this girlfriend….

SS says:  Oh, Jesus, Mary and Joseph!

And SP would say something like, "Oh, so you already know."

Correct punchline:

See, we're having contractual problems.  All the actors we want are in that other place...