As noted earlier here on the website, John Cena was in Las Vegas on Tuesday promoting his new fitness program. While he was advertised for the SmackDown tapings in Philadelphia, the feeling was that he would not be there because he would then have to fly back to Vegas for tomorrow's big WWE announcement. That turned out to be incorrect and just shows you how much of a workhorse Cena really is.
Following the TV taping, Cena hit the ring for a dark match main event at the WWE SmackDown taping in Philadelphia, PA. He wasn't booked on the live show - only the dark match main event.
Cena made the appearance on Tuesday in Las Vegas and then flew cross-country to Philadelphia for the match. He will now fly back to Las Vegas tomorrow for the WWE Network announcement.
Say what you want about John Cena .... but stuff like this needs to be respected and is one of the reasons WWE absolutely loves him.