While I'm not sure if they'd do a FFXV port, I do expect the FFVII remake to hit NX. Especially with Cloud now being in Smash. KH3 would also make sense too, although I feel like they would need to port the 1.5/2.5 HD Collections to NX as well as Nintendo's audience won't be fully familiar with the KH series.
I also get the feeling that we'll get a Mario Kart game for NX, most likely around the holiday season next year. Mario Kart is one of Nintendo's popular series and each system has a new installment. Plus, there's been a pattern... we've gotten a new Mario Kart every 3 years since Mario Kart DS. (2005 for DS, 2008 for Wii, 2011 for 7, 2014 for 8) Mario Kart NX coming out in 2017 would make perfect sense.