Their handhelds are getting close to the power of the last gen (PS2/XB1) consoles, so that's not a bad move for them to focus solely on the portable systems. They more or less own the market (bar the rapid rise in popularity of phones as gaming systems)
If Ninty does leave the console market next generation, it would be very interesting to see if they still used their licenses for Sony and Microsoft, much like Sega does now. If they made an exclusive deal with one (Sony, due to their strength in Japan?) that would give that console a massive advantage.
Looking For: Wreckers Saga TPB Collection (with Requiem)