Not that I don't think some extra spice to the recent Mario platformers would be welcome, and I haven't played NSMB2 yet, but I think Mr. Sterling's arguments are pretty poor. He doesn't really substantiate anything he says, he just keeps saying "Mario is getting repetitive and relies on nostalgia" for eight minutes.
I mean, he goes on to praise Rayman Origins (which is fine by me, I love that game), but, besides the amazing art, the big pull of that game (for me) was the four player platforming co-op... which was established/popularized with New Super Mario Bros. Wii.
Almost every Mario game has done something novel to justify its entry in the franchise, and I don't feel like the games are becoming a drag at all. They change just as much, if not moreso, between sequels as most any other popular industry franchise.