Regarding future Metroid games:
Internally, Nintendo of America considers the following as its tentpole / marquee franchises:
Code:
MARIO
POKEMON
DONKEY KONG / DIDDY KONG
ZELDA
YOSHI
STAR FOX
KIRBY
WARIO
METROID
I assume, given NOA's closeness to its parent company NCL (Kimishima / Iwata), that same policy would be reflected across recent game output.
After all, we've seen in the past two years:
Code:
MARIO[B] - NSMB U, NSL U, etc.[/B]
POKEMON [B]- Pokemon X / Y[/B]
DONKEY KONG / DIDDY KONG[B] - DK: TF[/B]
ZELDA [B]- Zelda: Wind Waker HD, Zelda Wii U, Zelda: A Link Between Worlds[/B]
YOSHI [B]- Yarn Yoshi and Yoshi's New Island[/B]
STAR FOX [B]- Star Fox 64 3D[/B]
KIRBY [B]- Kirby Mass Attack, Kirby: Return to Dreamland, Kirby Dream Collection, and most likely Kirby 3DS[/B]
WARIO [B]- Game and Wario[/B]
METROID
It's only Metroid that remains without some form of recent / announced title related to the IP.
Naturally, I bet Metroid is not going unnoticed by NCL. We even got a small teaser with the "Metroid Blast" minigame in Nintendo Land. While it may not be a big-budget Wii U production by Retro, I reckon some form of 2D Metroid exists within the depths of Nintendo SPD as a future, unannounced game.
You know, a reboot ala. Zelda: A Link Between Worlds for the 3DS.