If the only thing keeping Nintendo relevant is their first party software, I would expect them to go the way of Sega fairly quickly. I don't think Nintendo will be in the hardware business in 15 years unless they dramatically change their corporate culture and attitudes towards third party development. That means everything from who they allow to develop titles to what tools they provide for development. Given the overall level of enmity they've created amongst the indie development community and the large third party devs (thanks for telling everyone about the motion plus about half a year too late, jerks), I strongly doubt they'll win any hearts and minds. The only reason any third parties even bother with Wii dev now is because of the marketshare, even then, that marketshare has not resulted in the expected returns for most third parties.