Cena/Taker retirement match and Cena loses (so he can be with his wife and film a movie or two). That... would... blow people's minds. Plus when Cena came back, he'd be bigger than ever.
Honestly think it has to happen as you are good out both ways. Its wrestling so it would be easy to make it a double retirement somehow.
But ya, having Taker retire Cena so he can go do his thing would be shocking. So many things you could do with this match that it would be foolish NOT to do it.
Hell I would do it this year if Cena makes the miracle return as it gives Cena the out for the rest of the year to heal, and do his thing. Then rematch next year and he puts Taker out. I could see them having Taker walk off without "officially" retiring to leave the door open for future matches down the road (Finn etc.) open deal sort of thing. We know he is done, but you never know type of thing.
I'm not bored of deadman Taker, well I'm bored of how he does it recently with...the...long...pauses...
Keep the hat, the jacket, the 40 minute entrance, but talk normal. Honestly I don't want Taker cutting a long "real" promo in ring. Rather keep the real stuff for interviews after he is done.