Well probably a few large implications
1.) The whole "where did the Wii/DS audience go to?" mystery (for those who it was a mystery) has been answered fairly definitively I would think. Not only does iOS/Android have the mass market/casual audience Nintendo has been craving, it is *bigger* than even the peak DS/Wii audience. The casuals are on smart devices, they always were.
2.) Animal Crossing iOS/Android from a financial POV just became the most important game Nintendo has in development. If this becomes a big hit also ... Nintendo's stock price will skyrocket. Which likely means I think Nintendo is probably have some development meetings right now to ensure this game is something that will be a hit. IE: If they were kinda half-assing its development before, they definitely are not anymore. Fire Emblem is also important.
3.) All of Nintendo's IP catalog now likely has to be given consideration for mobile. Mario Kart. Smash Brothers (like that Marvel Heroes game). Zelda (touch based like the DS Zeldas), and some kind of Mario, and more Pokemon of course now likely have to happen in the next 2 years or less. Amiibo usage on smart devices will likely also happen (most phones/tablets have NFC readers).
4.) I don't think it means that they will try any less with the NX, *but* I think two realities are coming into pretty sharp focus -- mobile may become Nintendo's no.1 profit driver and Nintendo may well become the biggest mobile game maker in the world (for profit). Pokemon Go is just the tip of the ice berg, the Candy Crush and Angry Birds guys don't have Mario, Mario Kart, Zelda, Smash, Animal Crossing, Nintendogs, Tomodachi Collection, and many other IP that could be made into successful mobile product, not to mention Pokemon itself could have 3/4/5/6 different product lines on mobile.
5.) NX could be delayed now if Nintendo feels they need a bit more time. It always seemed like the March release date was really a "well we want something before the end of the fiscal year for our shareholders to feel happy about" type thing, but Pokemon Go pretty much ensures their stock price is going to be very strong through the fiscal year, so on that basis it isn't really the end of the world if they launch NX in May or June or September.