I don't think we'll see a new Metroid game announced next year, mainly because I think Nintendo will want to focus on Federation Force next year, but in 2017 I could see them announcing a reboot or a sequel to a mainline Metroid game for NX or whatever new console they have out.
I do think NX is going to be a new platform that basically breaks down the boundaries between handheld and home console, essentially a platform, without one specific type of hardware and for that Nintendo will have a new mainline 3D Mario game as a launch title, along with perhaps a version of Zelda updated for it or with additions that take advantage of the new platform.
Perhaps the new Pikmin will be a cross generation game, that can run on both Wii U and NX ecosystems.
Nintendo would be wise to have something like a Gears or Uncharted/The Last of us and a few other new IPs that target the western 3rd party audience, maybe they can get deals with Ubisoft or another big 3rd party publisher to make some cool new IPs outside of Nintendo's own style of play.
I think if a new Metroid is going to happen then it will be a while until we hear about it, though anything is possible with Nintendo.
Hopefully they'll have a developer make a fully open world, 3D Pokemon action RPG, this kind of a game would push a lot of hardware IMO, especially the handheld portion of the platform, assuming it's a hybrid platform based system.
