Punk watching Cena get punished by Big Show may be a little more puzzling. Cena became the first Superstar ever to cash in a Money in the Bank championship contract and not win a championship despite not losing the match. In fact, Cena won by disqualification when Big Show attacked him. Regardless of how the match ended, though, the fact of the matter is that Cena had one, and only one, opportunity to cash in and challenge for the WWE Championship. And now that opportunity is gone.
Officially, Cena is not due a WWE Championship rematch.