Nah, most of his opponents at PPVs have been midcarders including Bryan. Orton is far bigger star and he will be his first main event threat. Orton/Sheamus is the right call for Mania 29.
What kind of a threat is he? Orton is a joke right now, he tapped out to Alberto Del Rio and Big Show, a glorified main event jobber beat him handily. Sheamus has already beaten Orton clean too. It's not the right call, it will not get him more over, and even if it would, it's still the wrong call. We need OTHER stars. The WWE has a serious lack of depth. WWE desperately needs someone who has not been champion before to win at Mania.