It's being claimed that Nintendo will reveal the NX this September, most likely at the Tokyo Game Show.
French site Gameblog suggests that the console is similar in power to the PS4K and has some third-party exclusives in the works from Capcom and Square Enix. It's also claimed that Skyward Sword is being remastered for the system, while there are also new titles in both the Mario Kart and Super Smash Bros series planned.
It makes sense for Nintendo to reveal the NX at the Tokyo Game Show as its console is currently performing better in the far east than anywhere else. It also makes sense that Sony may take the opportunity to reveal the PS4K at Tokyo Game Show to steal some of Nintendo's thunder, especially with the NX said to be more powerful than the current PS4.
This is all rumour and speculation of course. But what do you think?