Dinner theater's been done. I've never actually been to one, so I don't know what I'm talking about, but I never let that stop me.
How-to-host-a-murder dinner parties I have much more experience with. Fun, costumed entertainment -- amount of fun varies directly with energy committed by attendees. The usual pattern is lots of obvious misdirection and all the clues don't really coalesce until the final round.
But have you ever gone out to eat at a restaurant and had somebody pass you a manila envelope while you ate?
So the real question is only... what other insanely cool things could be part of a game like that?