One of the things that will determine the Switch’s long term success is how easy it will be to develop games for the system. In the past, Nintendo systems have not been easy to port games to, or develop games for, because of their eccentric architecture, or unique bottlenecks. With the Switch, Nintendo is trying to counter that problem with a unique development environment developed by none other than Nvidia. In fact, Nvidia itself has said that porting existing PS4 or Xbox One games to the Switch should be very easy.
According to Nintendo’s Shigeru Miyamoto, that is true- a game developed for the PC as a base can be ported to the Nintendo Switch in just a year, Miyamoto confirmed to GamesIndustry.jp (via Nintendo Everything). He also mentioned that there are a lot of western third party games in the works for the Switch, but that Nintendo held off on announcing them, suggesting instead that they will announce them come E3.
Although I do expect that to be true to some extent, I am not sure just what the extent of western third party support on the Switch will be. If the Switch is successful, it will be successful on the back of Nintendo’s own games, as well as indie games and Japanese third party games.