It wouldn't.
Mario and Pokémon are pretty much the only character driven franchise that Nintendo can rely on to produce the sales figures anymore. And as for their Wii created casual properties, their success will very much depend on how many they can persuade to make the transition over to Wii U.
Sony have in Naughty Dog arguably last generations hottest and most anticipated developer (Uncharted, The Last of Us). Likewise they also have Quantic Dream (Heavy Rain, Beyond) and Team Ico.
Along with first party franchises such as Gran Turismo, God of War, Infamous, Killzone, Resistance, LittleBigPlanet, Ratchet & Clank, Sly Cooper etc... indie developers ThatGameCompany and Giant Sparrow.
Grand Theft Auto and Metal Gear are also two of the biggest gaming franchises and most associated with their consoles.