Well, we don't know that for sure. To the best of my recollection, he's never had a PPV match before, and you know how WWE likes to save the best work for the PPVs, so maybe they're hiding what Orton can really do until Summerslam.
I think that SS will be a defining moment in Randy Orton's career, if only because it has to be. He's in the main event of the 2nd-biggest PPV of the year, and it's only his first-ever "big" match. It's very possible that he could bust out some sick stuff that none of us could ever have pictured him doing, and maybe even change our whole perspective of him.
Hell, the Elimination Chamber match could be a classic if all 6 participants just went in there and gave 'er. We know that HHH, HBK, Goldberg and even Nash have it in them to pull off some excellent matches; the only question is if they do so. There's a little part of me inside that wishes, if only for one show, that a few of the guys constantly ragged on here (example: Nash, Test, La Rez, etc.) would go out there and pull off a **** or better match, just to show us smart marks up. That's why I still watch RAW: to see if maybe, just maybe, they can do something that'll make us say "You know, I may hate (insert name of smark whipping boy) a lot, but damn... that was good." Maybe this Sunday is the time. Maybe.